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What does an elevated hematocrit mean: 9 common nutrient deficiencies in the U.S.


9 common nutrient deficiencies in the U.S.

Although most of us are aware of the benefits of eating a balanced diet, nearly 10% of people in the U.S. have nutrient deficiencies. Failing to get key nutrients can lead to a variety of health problems, including fatigue, night blindness, osteoporosis, high blood pressure, and even acne.

If you’re experiencing the above symptoms and have ruled out other health conditions, you may suffer from a nutrient deficiency. Preventing and detecting the most common ones—including calcium, essential fatty acids, folic acid, iron, magnesium, and vitamins A, B12, C, and D—can be achieved through monitoring and adjusting your diet, considering dietary supplements, and having a conversation with your healthcare provider if you suspect you have a vitamin or mineral deficiency.

What is a nutrient deficiency, and how do I know if I have one?

“A nutrient deficiency occurs when a body doesn’t get the necessary amount of nutrients it needs (a nutrient being a substance that is essential for growth, development, or the maintenance of life),” says Michael Jay Nusbaum, MD, the medical and surgical director at Nusbaum Medical Centers in New Jersey. 

Many people have vitamin deficiencies but never realize it. Those who maintain a poor diet, eat poor quality food, or fail to take supplements are most at risk. In many cases, symptoms lead to a patient getting testing, which reveals the deficiency.

Once a nutritional deficiency is detected, it’s treated by providing the nutrients needed in the diet either through food, supplements, or both. In some severe deficiency cases, IV infusions may be necessary to replenish what is missing, according to Dr. Nusbaum. 

9 common nutrient deficiencies

In the U.S., calcium, essential fatty acids, folic acid, iron, magnesium, and vitamins A, B12, C, and D are some of the most common nutrient deficiencies.

1. Calcium

Calcium’s main reputation comes from being an important building block for strong bones. But the essential mineral is also key for nerve and muscle function and heart health. Because calcium is stored in the bones and withdrawn when we don’t consume enough, a calcium deficiency leaves bones weak and more likely to break. 

Nearly 70% of Americans fail to meet the recommended daily intake for calcium, which is due to either inadequate intake of calcium-rich foods or to poor absorption. Additionally, caffeinated beverages, alcohol, soda, dark leafy greens, beans and whole grains can decrease the body’s absorption of calcium. Signs of a calcium deficiency include mottled teeth, weak fingernails, or a numbness/tingling in the fingers or muscle cramps.

2. Essential fatty acids

“Essential fatty acid deficiencies occur when omega-3 consumption is too low, but symptoms can also appear if omega-6 fatty acid intake from processed foods is too high,” says Paul Kriegler, RD, the nutritional products program manager at Life Time. Symptoms include scaly skin, brittle or cracking nails, and acne.

3. Folic acid

Folic acid, one of the many B vitamins, plays a role in maintaining healthy red blood cells and is particularly important during pregnancy, as women with low folic acid stores have a greater chance of having a baby with a neural tube defect (such as spina bifida). Outside of pregnancy, folic acid helps prevent anemia and heart disease.

Those who don’t consume enough fruits and vegetables (or who overcook their veggies) are at the greatest risk of developing a folate deficiency. People who consume high amounts of alcohol or who take certain medications (such as phenytoin, methotrexate, sulfasalazine, triamterene, trimethoprim-sulfamethoxazole, and barbiturates) have an increased risk of developing a folic acid deficiency. Symptoms may be similar to those caused by an iron deficiency, including fatigue, lethargy, hair loss, and shortness of breath.

RELATED: 3 types of medications that could have a vitamin interaction



“Iron deficiencies can occur multiple ways: inadequate consumption of iron-rich foods, poor iron absorption, or iron loss through excess blood loss or during developmental stages in life such as adolescence, pregnancy, or breastfeeding,” Kriegler says. Other people who have an increased risk of developing an iron deficiency include those with certain stomach or intestinal conditions that either cause bleeding or reduce the absorption of iron from food.

Iron deficiency anemia can cause general fatigue, headaches, dizziness, shortness of breath, muscle weakness, pale skin color, and chest pain. In pregnant women, iron levels should be routinely checked, as expectant mothers are at an increased risk of developing this condition.

5. Magnesium

Magnesium is an essential mineral that affects hundreds of metabolic reactions within the body, including regulating muscle and nerve function. “Many Americans don’t consistently consume adequate amounts of magnesium and most multivitamin supplements contain insufficient amounts of magnesium because it’s a bulky mineral that takes up a large volume of space in the formula, so it’s often recommended as an additional, stand-alone supplement,” notes Kriegler. Symptoms of a magnesium deficiency include muscle cramps, abnormal heart rhythms, unexplained numbness or tingling, and high blood pressure. 

6. Vitamin A

Vitamin A is essential in the replacement of skin cells and for maintaining optimal vision and a healthy immune system. For this reason, those with a vitamin A deficiency are at an increased risk of acquiring a severe infection. As children are prone to infections, it’s crucial that those under the age of 5 get enough vitamin A in their diets or through supplements. In adults, one of the key warning signs of a vitamin A deficiency is night blindness.

7. Vitamin B12

One of the eight types of B vitamins, vitamin B12 helps to form red blood cells, enhances neurological function, and provides building blocks for DNA. Those most at risk for a vitamin B12 deficiency are vegans, people with intestinal problems that limit vitamin absorption, older adults, and those taking long-term heartburn medication. Symptoms of vitamin B12 deficiency are similar to those of anemia, including weakness, pale skin, shortness of breath, and mood changes.

8. Vitamin C

Vitamin C acts as an antioxidant within the body, helping to prevent damage inflicted by free radicals. Vitamin C also helps in hormone and amino acid formation; it also helps with the absorption of iron. The most commonly known effect of a vitamin C deficiency is scurvy, a fatal-if-untreated disease that causes inflamed and bleeding gums, easy bruising, weakness, fatigue, rashes, and difficulty healing wounds. While scurvy is uncommon today, proper vitamin C intake is still crucial for optimal health, as vitamin C regulates collagen production.

9. Vitamin D

Vitamin D is unique in that most vitamin D can be produced in our bodies when exposed to adequate amounts of UVB radiation from sunlight. Vitamin D’s key role is to regulate calcium absorption. Those with a vitamin D deficiency are unable to absorb that calcium and in turn strengthen bones. However, vitamin D has several other important roles for overall health, including supporting bone health, cardiovascular health, testosterone, and immune function.

The NIH says that “35% of adults in the United States are vitamin D deficient.” Try to get 10-15 minutes of mid-day sun exposure of the face, hands, and arms without protective sunscreen may be enough to maintain healthy vitamin D levels, depending on the time of year, latitude, and skin pigmentation characteristics. Remember, if your skin is starting to turn pink, you’ve gotten too much sun.

RELATED: How much vitamin D should I take?

How to prevent nutrient deficiencies

“The simplest way to prevent nutrient deficiencies is to eat a wholesome, nutrient-dense diet based on an abundance of produce (seven-plus servings per day) and ample protein, plus supplementing your diet every day with a high quality multivitamin, vitamin D, and omega-3 fish oil,” says Kriegler. If you’re concerned about a nutrient deficiency, there are a few steps you can take:

Get tested

Your healthcare provider can order a blood test to evaluate your essential nutrient levels if you’re exhibiting symptoms of a deficiency. An individual blood test can be conducted to assess a specific nutrient deficiency. However, a comprehensive nutrition panel is the most effective way to measure your overall health according to levels of vitamins, nutrients, and enzymes. Overnight fasting may be recommended to enhance the accuracy of results.

Evaluate your diet

Getting nutrients from your diet while avoiding processed foods, fast foods, and sugars is the ideal way to avoid a nutrient deficiency. Food sources include:

  • Calcium: Dairy products (milk, yogurt, or cheese), sardines, calcium-fortified orange juice, and dark green leafy vegetables
  • Folic acid: Eggs, leafy green vegetables, fruits, and dried beans and peas
  • Essential fatty acids: Cold water fish, flaxseed, and olive oil
  • Iron: Fortified dairy products, fatty fish, egg yolks, red meat, poultry, fish, and beans or legumes
  • Magnesium: Pumpkin seeds, leafy green vegetables, beans, legumes, and whole grains
  • Vitamin A: Spinach, chard, sweet potatoes, squash, pumpkins, carrots, mangoes, papayas, eggs and milk
  • Vitamin B12: Meat, fish, poultry, eggs, and dairy products
  • Vitamin C: Citrus fruits, broccoli, cantaloupe, cauliflower, kiwi, sweet potatoes, tomatoes, kale, bell peppers, and strawberries
  • Vitamin D: Fatty fish, beef liver, egg yolks, or a number of fortified foods (however, it’s almost impossible to achieve optimal vitamin D levels solely through diet, notes Kriegler)

Consider supplements

Even with a healthy diet, it can be difficult to achieve an optimal balance of nutrients. Supplements containing essential nutrients are available either alone, or in multivitamin formulas; your healthcare provider or pharmacist can help you determine the right balance of supplements.

Polycythemia Vera Diagnosis | Leukemia and Lymphoma Society

While a person may have certain signs and symptoms of polycythemia vera (PV), laboratory tests are needed to confirm the diagnosis. Generally, a doctor will consider other conditions first.

Sometimes a condition called “secondary polycythemia” is causing the increase in red blood cells but, unlike PV, it does not begin in the bone marrow and is not a cancer. High red blood cell counts caused by secondary polycythemia are a reaction to another problem such as: 

  • High altitude
  • Disease that leads to low oxygenation of the blood
  • Kidney or liver tumor that secretes the hormone erythropoietin
  • Inherited disease

Secondary polycythemia is managed primarily by treating the underlying condition causing the disorder. A patient with secondary polycythemia should have a return to normal red blood cell counts once the primary problem is successfully treated.


Medical History and Physical Examination

Evaluation of an individual with suspected PV should start with a detailed medical history and a physical examination by a hematologist-oncologist

The medical history should include information about the patient’s:

  • Cardiovascular risk factors
  • Past illnesses
  • Injuries
  • Treatments
  • Medications
  • A history of the formation or presence of a blood clot inside a blood vessel (thrombosis) or loss of blood from damaged blood vessels (hemorrhagic events)
  • History of blood relatives—some illnesses run in families
  • Current symptoms

After the medical history, the doctor will conduct a physical examination. During the physical examination, the doctor may:

  • Listen to the patient’s heart and lungs
  • Examine the patient’s body for signs of disease
  • Check different organs of the body


Blood Tests

Complete Blood Count

This test measures the number of red blood cells, white blood cells and platelets in a sample of blood. It also measures the amount of the iron-rich protein that carries oxygen in red blood cells and the percent of whole blood made up of red blood cells (the hematocrit). People with PV have high red blood cell counts. They also often have:

  • Increased white blood cells and platelets
  • Increased hemoglobin levels
  • Increased hematocrit levels

Red Cell Mast Test

This procedure is used to measure the volume (amount) of red blood cells in relation to the volume of plasma (fluid) in whole blood. In patients with PV, there may be an absolute increase in red blood cell mass. This test is infrequently performed in the United States due to high cost, difficulty obtaining the appropriate test materials, and the advent of new blood tests such as mutational testing.

Peripheral Blood Smear

A procedure in which a blood sample is viewed under a microscope. A pathologist examines the sample to see if there are any unusual changes in the size, shape and appearance of various blood cells. The test also checks for the presence of immature (blast) cells in the blood. 

Comprehensive Metabolic Panel

These tests measure the levels of substances released into the blood by organs and tissues. These include electrolyes, fats, proteins, glucose (sugar) and enzymes. Blood chemistry tests provide important information about how well a person’s kidneys, liver and other organs are working. For patients suspected of having PV, it is important to test the serum erythropoietin level. Erythropoietin is a hormone naturally produced by the kidneys to stimulate the production of new red blood cells. Individuals with PV usually have very low levels of erythropoietin. 


Bone Marrow Tests

Your doctor may examine your bone marrow even though the test isn’t needed to diagnose PV.

Bone marrow testing involves two steps usually performed at the same time in a doctor’s office or a hospital:

  • A bone marrow aspiration to remove a liquid marrow sample
  • A bone marrow biopsy to remove a small amount of bone filled with marrow

In PV, the bone marrow shows above-normal numbers of blood cells and an abnormal number of the platelet-forming cells called “megakaryocytes” in the bone marrow. The pathologist also examines the chromosomes of the bone marrow cells to rule out other blood diseases. 


Molecular Testing

Molecular genetic tests are very sensitive tests that look for specific gene mutations. If PV is suspected, molecular testing for the JAK2 mutation should be performed. The JAK2 V617F mutation is found in more than 90 percent of PV patients.

The U.S. Food and Drug Administration (FDA) has approved a test called ipsogen JAK2 RGQ PCR Kit to detect mutations affecting the Janus Tyrosine Kinase 2 (JAK2) gene. This test is intended to help doctors evaluate patients for suspected PV.

For more information about bone marrow tests and other lab tests, please see the free LLS publication Understanding Lab and Imaging Tests.


Criteria for Diagnosing Polycythemia Vera

In 2016, the World Health Organization published new criteria for diagnosing PV. The diagnosis of PV requires the presence of

  • Major Criteria 1, 2, and 3 (listed below) or
  • Major Criteria 1 and 2 and the minor criterion(listed below) 

Major Criteria 1.  Very high red blood cell count, usually identified by either A, B, or C below:

  • A. Hemoglobin level
    • Elevated levels of hemoglobin
      • Hemoglobin levels greater than 16.5 g/dL in men
      • Hemoglobin levels greater than 16.0 g/dL in women
  • B. Hematocrit level
    • Elevated levels of hematocrit
      • Hematocrit greater than 49 percent in men
      • Hematocrit greater than 48 percent in women
  • C. Red cell mass

Major Criteria 2. Bone marrow biopsy (A or B below) showing:

  • A. An abnormal excess of blood cells in the bone marrow (called “hyercellularity”) with an elevation of red blood cells, white blood cells and platelets (called “panmyelosis”)
  • B. Proliferation of mature megakaryocytes that vary in size and shape

Major Criteria 3. Presence of the JAK2V617F or JAK2 exon 12 gene mutation

Minor Criterion: Very low levels of erythropoietin


Related Links

Hematocrit – Complete Blood Count

Hematocrit – Complete Blood Count


The hematocrit,
also known as the “Hct“, “crit
or PCV (packed cell volume) determines the percentage of red
blood cells in the plasma. The term hematocrit means “to separate blood.”
When the patient’s blood sample is spun in a centrifuge, the white blood cells
and platelets rise to the top in what is known as the “buffy coat.”
The heavier red blood cells sink to the bottom, where they can be calculated
as a percentage of the total blood sample.

Normal hematocrit values

  • Newborn: up to
  • Adults: (males):
    40- 54%
  • (Females): 36
    – 46%
  • Pregnancy: decreased
    hematocrit, especially in the last trimester as
    plasma volume increases
  • Children: varies
    with age

If the RBC
and the hemoglobin are both normal, it is possible to estimate
the hematocrit as being approximately three times the hemoglobin. For example,
a person whose hematocrit is 30% would have a hemoglobin of approximately 10


women normally have a drop in hematocrit in the last trimester of pregnancy.

Because the hematocrit
is a percentage of red blood cells, as compared to the total volume of blood,
any increase or decrease in plasma volume affects the hematocrit.
A patient with a severe burn loses huge amounts of plasma from damaged capillaries.
As a result, the vascular space loses fluid in relation to cellular elements
and the patient’s hematocrit will be significantly increased.
A decreased hematocrit occurs due to overhydration, which lowers
the percentage of red blood cells in relation to the liquid plasma portion of

A hematocrit
is frequently done to assess the extent of significant blood loss. A hematocrit
that is done immediately after a hemorrhage usually does not show the extent
of RBC loss because at the time of the hemorrhage, plasma and red blood cells
are lost in equal proportions. However, within several hours after hemorrhage,
plasma volume increases due to a shift of interstitial fluid into the vascular
space. Red blood cells, however, cannot be replaced quickly, as the bone marrow
takes approximately ten days to produce mature red blood cells. As a result,
a hematocrit done several hours after a bleeding episode will
show a more accurate picture – the hematocrit will be decreased
because the plasma volume has compensated for fluid loss while the red blood
cells that have been lost cannot be replaced for days. It is important for the
nurse to remember that a hematocrit value must always be interpreted
in relation to the patient’s hydration status and to the time the sample was
drawn. When packed red blood cells are given to correct an anemia, the hematocrit
should rise approximately 3% for each unit transfused.

How a patient responds to
a low hematocrit depends on whether the blood loss is acute
or chronic. If a person with a normal blood cell volume loses blood suddenly
through a massive hemorrhage, the person may develop signs and symptoms of circulatory
shock; the blood pressure will fall and the patient will show signs of tissue
hypoxia and shock. However, a person with chronically low hemoglobin, such as
a patient on renal dialysis, may tolerate abnormally low hemoglobin. A major
reason for anemia in patients with renal failure is lack of erythropoetin to
stimulate bone marrow production.


a patient’s hematocrit to drop immediately after major hemorrhage.

Hematocrit: critical
low and high values:

  • A hematocrit
    of less than 15%
    can result in cardiac failure
  • A hematocrit
    of over 60%
    may result in spontaneous blood clotting


© RnCeus.com


Hematocrit: High or Low? All You Need to Know

Hematocrit is the percentage of red blood cell volume compared to your total blood volume. Red blood cells carry oxygen throughout the body to help power biological functions. More oxygen may mean improved cognition and increased endurance.

What Is Hematocrit?

Hematocrit (also called HCT, packed cell volume, or PCV) is measured by routine lab tests. It is the percentage of red blood cells in your blood or, in other words, the volume of red blood cells divided by the total blood volume [1, 2, 3].

Red blood cells come from the bone marrow, where they are made from stem cells. The body makes about 2 million red blood cells every second. Every red blood cell lives about 120 days and then eventually ages, dies, and is broken down by the spleen [4].

Red blood cells carry oxygen, so an increase in hematocrit also increases the ability of the blood to carry oxygen. However, higher hematocrit also increases the thickness (viscosity) of blood, reducing its ability to flow through small blood vessels and reach the tissues in the body. Therefore, higher hematocrit isn’t always better for health [5].

Hematocrit affects a variety of processes, from throwing off the accuracy of blood sugar measurements to controlling the behavior of platelets and blood clotting proteins [6, 7, 8].

Based on a hematocrit measurement, it is possible to calculate other values that are used to predict, estimate, or evaluate [9, 10, 11, 12, 13, 14, 15, 16]:

  • Disease risk
  • Disease severity
  • Surgery-related risks
  • Blood viscosity (which is related to blood flow)
  • Blood loss
  • Rate of treatment (e.g., a dose) needed

Test results vary based on a number of factors, ranging from what kind of device is used to take the measurement to whether you have been drinking enough fluids [17, 2].

Dehydration is a common cause of high hematocrit results [2].

Sitting up (as opposed to lying down) during a blood draw can also increase your results [18].

Normal Values

Lab results are commonly shown as a set of values known as a “reference range”, which is sometimes referred to as a “normal range”. A reference range includes the upper and lower limits of a lab test based on a group of otherwise healthy people.

Your healthcare provider will compare your hematocrit levels with reference values to see if your results fall outside the range of expected values. By doing so, you and your healthcare provider can gain clues to help identify possible conditions or diseases.

Remember that some lab-to-lab variability occurs due to differences in equipment, techniques, and chemicals used. Don’t panic if your result is slightly out of range in the app – as long as it’s in the normal range based on the laboratory that did the testing, your value is normal.

However, it’s important to remember that a normal test doesn’t mean a particular medical condition is absent. Your doctor will interpret your hematocrit results in conjunction with your medical history and other test results.

But remember that a single test isn’t enough to make a diagnosis. Your doctor will interpret this test, taking into account your medical history and other tests. A result that is slightly low/high may not be of medical significance, as this test often varies from day to day and from person to person.

Normal hematocrit ranges are 40 to 54% for men, 36 to 48% for women, and 30 to 43% for children [2].

However, typical hematocrit can vary between populations depending on both genetic and environmental factors as well as the different measurement techniques used [19].

Hematocrit can vary from day to day or on a more long-term basis depending on altitude, season, athletic training, diet, and pregnancy, among other factors [20, 21, 22, 23, 24].

Hematocrit is a useful diagnostic tool because it can change in generally predictable ways with a health problem [25].


In polycythemia, your blood contains a higher-than-normal proportion of red blood cells. Polycythemia can be “primary,” meaning that there is a problem with the way that your body is making red blood cells, or “secondary,” meaning that the problem is an adjustment to some other influence. For example, your body may be making more red blood cells because it’s not getting enough oxygen [26].

Symptoms of polycythemia can include:

  • Blurred vision
  • Bruising
  • Dizziness
  • Fatigue
  • Headaches
  • Joint pain
  • Stomach pain
  • Weakness

High hematocrit can increase eye pressure, PO2 (the amount of oxygen in your blood), muscle oxygenation, and hand grip strength [27, 28, 29, 30].

High hematocrit can reduce the rate of clearance of a drug from your body and slow down blood flow [31, 32].

The following conditions are commonly associated with high hematocrit levels, but this single symptom is not enough for a diagnosis. Work with your doctor to discover what underlying condition might be causing your unusually high value in this test and to develop an appropriate plan to improve your health:

  • Capillary leak syndrome (leaky blood vessels) [33]
  • Congenital adrenal hyperplasia (misregulated steroid hormones) [34]
  • Cystic fibrosis [35]
  • Dengue fever [36]
  • Ebola [37]
  • Eclampsia (pregnancy complications) [38]
  • Erythrocytosis (high red blood cells) [39]
  • Heart disease
  • Hypertension (high blood pressure) [40]
  • Hyponatremia (low blood sodium) [41]
  • Hypoxia (low oxygen) [42, 43]
  • Insulin resistance [44]
  • Metabolic syndrome [45]
  • Mountain sickness (at high altitudes) [46]
  • Non-alcoholic fatty liver disease [47]
  • Necrotizing pancreatitis (e. g., from alcohol abuse) [48, 49]
  • Sleep apnea (breathing pauses during sleep) [50]
  • Ovarian hyperstimulation syndrome (e.g., from fertility treatments) [51]
  • Kidney disease [52]
  • Polycythemia vera (a blood cancer) [53]
  • Posterior reversible encephalopathy syndrome (e.g., from high blood pressure) [54, 55]
  • Postpartum depression [56]
  • Prediabetes [57]
  • Retinopathy (eye blood vessel damage) [58]
  • Shock [59]
  • Thrombocythemia (high platelets)
  • Thrombosis (blood clot) [60]

When High Levels Are Good

High hematocrit has a number of potential health benefits. It can:

  • Increase cognitive function [61]
  • Improve athletic performance [62]
  • Reduce aging [63]
  • Reduce the risk of ulcers [64]
  • Reduce the risk of cavities [65]
  • Reduce the risk of death from heart failure [66]

When High Levels Are Bad

The following diseases have been associated with high hematocrit levels. Remember that the studies haven’t established this parameter as their cause. Having a high hematocrit value doesn’t necessarily mean that you will develop these conditions:

  • Stroke [67]
  • Heart disease [68]
  • Poor outcomes in amyotrophic lateral sclerosis [69]
  • Poor outcomes in sepsis (inflammatory response to infection) [70]
  • Poor outcomes in gangrene [71]


Low hematocrit, or anemia, can be caused by blood loss, the body making fewer red blood cells, or increased destruction of red blood cells. Symptoms of anemia can include difficulty breathing, dizziness, headache, cold skin, pale skin, and chest pain [72].

In some cases, anemia can be signaled by pica, a craving for unusual foods or nonfood substances (e.g., ice, crunchy foods, salty foods, clay, dirt) that goes away with iron supplementation [73].

The following conditions are commonly associated with low hematocrit levels, but this single symptom is not enough for a diagnosis. Work with your doctor to discover what underlying condition might be causing your unusually low value in this test and to develop an appropriate plan to improve your health:

  • Alzheimer’s disease [74]
  • Anemia [75]
  • Arthritis
  • Autism spectrum disorder [76]
  • Bipolar disorder [77]
  • Bone marrow disorders
  • Cerebral palsy [78]
  • Cirrhosis (liver disease) [79]
  • Depression [80]
  • Dyspepsia (stomach problems) [81]
  • Dyspnea (breathing problems) [82]
  • Fibromyalgia [83]
  • Growth hormone deficiency [84]
  • Hematoma (abnormal collection of blood) [85]
  • Hemophilia (a bleeding disorder) [86]
  • HIV [87]
  • Hypotension (low blood pressure) [88]
  • Hypothermia [89]
  • Infection
  • Inflammatory diseases
  • Kidney disease or failure [90]
  • Leukemia
  • Massive blood loss (e.g., from trauma, cancer, internal bleeding)
  • Nutritional deficiency (e.g., low iron, folic acid, vitamin B12) [79]
  • Parasitemia (parasites in the blood, e.g., in malaria) [91]
  • Periodontitis (gum disease) [92]
  • Sepsis (inflammatory response to infection) [93]
  • Shock
  • Sickle cell disease [94]
  • Systemic sclerosis (an autoimmune disease) [95]
  • Thalassemia
  • Type 1 diabetes [96]

When Low Levels Are Good

Low hematocrit has some potential health benefits. It can [62, 97]:

  • Increase VO2 max (the maximum amount of oxygen you can use during intense exercise)
  • Reduce the risk of seizures

When Low Levels Are Bad

There are health risks associated with low hematocrit. Low hematocrit can increase the length of hospital stay after surgery. It also can increase the risks of [98]:

  • Complications from surgery [99]
  • Surgical site infection [100]
  • Hospital readmission after surgery [101]
  • Need for blood transfusion [102]
  • Tuberculosis [103]
  • Ischemia (restricted blood flow to part of the body) [104]
  • Poor outcome from injury [105, 106]
  • Poor outcome from pneumonia [107]

Remember that the studies haven’t established this parameter as the cause of these complications. Having a high hematocrit value doesn’t necessarily mean that you will develop these conditions.

How to Increase Hematocrit

You may be increasing your hematocrit, or naturally have higher hematocrit, without realizing it. This may be due to:

  • Adjusting to a high altitude [108]
  • Alcohol consumption [109]
  • Being male [110]
  • Being overweight [111]
  • Mental stress [112]
  • Military training [113]
  • Smoking cigarettes [114]
  • Spaceflight [115]
  • Workplace pollution [116, 117]
  • Your sleeping position (head tilted downward) [118]

How to Increase Levels Naturally

If your hematocrit value is too low, the most important thing is to work with your doctor to find out what’s causing this low value and to treat any underlying conditions. The additional lifestyle changes listed below are other strategies you may want to discuss with your doctor. None of them should ever be implemented in place of what your doctor recommends or prescribes!

You can increase your hematocrit by consuming foods or supplements that increase iron. For example, you can increase your hematocrit by eating or drinking [119]:

  • Almonds
  • Artichokes
  • Beans
  • Chickpeas
  • Dried fruit
  • Fermented foods
  • Fish and shellfish
  • Flaxseed oil
  • Green, leafy vegetables
  • Iron-fortified foods
  • Lentils
  • Millet (shown by an animal study)
  • Molasses
  • Pomegranate juice
  • Prune juice
  • Pumpkin seeds
  • Soybeans or tofu

Because vitamin C helps the body absorb iron, you can increase hematocrit by consuming fruits and vegetables that are rich in vitamin C, such as [119]:

  • Broccoli
  • Brussels sprouts
  • Cabbage
  • Cantaloupe
  • Kiwi
  • Peppers
  • Potatoes
  • Strawberries
  • Tomatoes

In addition, copper helps prevent anemia by helping with iron storage and absorption. You can increase hematocrit by consuming foods that are rich in copper, such as:

  • Cashews
  • Sesame seeds
  • Shiitake mushrooms
  • Sunflower seeds
  • Tempeh
  • Walnuts

Medical Treatments that Increase Levels

Hematocrit can be increased medically with:

These treatments often have other purposes than increasing hematocrit levels and must always be conducted under medical supervision.

Drugs That Increase Levels

Some drugs may increase your hematocrit value if you are already taking them for some other health condition, but never start taking them or increase your dose for this purpose. Always follow the treatment plan prescribed by your doctor.

Drugs used for treating hypogonadism (inadequate testosterone), organ transplant recipients, anemia, surgical blood loss (reducing blood loss), uterine fibroids, Crohn’s disease, and arthritis can increase hematocrit [125, 126, 127, 128, 129, 130, 131, 132].

Hematocrit can also be increased as a result of taking:

How to Reduce Hematocrit

You may be reducing your hematocrit without realizing it due to:

  • Being a farmer [140]
  • Being a trained athlete [141]
  • Being pregnant [142]
  • Contaminated drinking water [143]
  • Exposure to allergens [144]
  • Workplace pollution [145]

How to Reduce Hematocrit Naturally

If your hematocrit value is too high, the most important thing is to work with your doctor to find out what’s causing this high value and to treat any underlying conditions. The additional lifestyle changes listed below are other strategies you may want to discuss with your doctor. None of them should ever be implemented in place of what your doctor recommends or prescribes!

You can reduce your hematocrit through the following dietary modifications:

  • Avoiding iron supplements [146]
  • Eating more bran (it interferes with iron absorption) [147]
  • Staying hydrated [148]
  • Avoiding alcohol [109]
  • Eating more grapefruit [149]
  • Getting more antioxidants [150]

Additionally, you can try the following lifestyle interventions:

  • Doing moderate exercise [151, 152, 153]
  • Moving to a lower altitude [108]
  • Giving up smoking [114]

Medical Treatments that Reduce Levels

Hematocrit can be reduced medically by (or as a side-effect of):

  • Blood donation [154]
  • Anesthesia [123]
  • Cardiopulmonary bypass (artificial circulation during surgery) [155, 156]
  • Immunoglobulin treatment [157]
  • Positive airway pressure therapy for sleep apnea [158]
  • Radiation therapy [159]

These treatments often have other purposes than lowering hematocrit levels and must always be conducted under medical supervision.

Drugs That Reduce Levels

Some drugs may reduce your hematocrit value if you are already taking them for some other health condition, but never start taking them or increase your dose for this purpose. Always follow the treatment plan prescribed by your doctor.

Drugs for mountain (altitude) sickness, polycythemia vera (a blood cancer), type 2 diabetes, male contraception, and malaria can reduce hematocrit [160, 161, 162, 163, 164].

Hematocrit can also be reduced as a result of taking:

  • ACE inhibitors (for, e.g., high blood pressure) [165]
  • Aspirin [166]
  • Desmopressin [167]
  • Finasteride [168]
  • Glycerol [169]
  • Ibuprofen [170]
  • Metformin [171]
  • Misoprostol [172]
  • Rivaroxaban [173]
  • Tocolytic agents [174]

Hematocrit Genetics

Hematocrit levels are influenced by your genes.

If you’ve gotten your genes sequenced, SelfDecode can help you determine if your levels are high or low as a result of your genes, and then pinpoint what you can do about it.

If you’re sick and tired of guessing about your health, SelfDecode can help you find specific answers that conventional doctors/diagnostics may never uncover.

Gene SNPs Effect
ABO rs2073823 Hematocrit higher for AA genotype [175]
AKT3 rs4590656 Hematocrit higher for CT genotype [176]
AQP1 rs1049305 Hematocrit higher for GG genotype [175]
AQP1 rs10244884 Hematocrit higher for TT genotype [175]
EPAS1 rs6756667 Hematocrit higher for GG genotype, compared to AG genotype, during the development of mountain sickness [177]
EPO rs551238 Hematocrit higher with G allele [178]
EPO rs1617640 Hematocrit higher with G allele [178]
EPO rs62483572 Lower hematocrit with D70N mutation [179]
EPOR rs121918116 Hematocrit higher with A allele [180]
FTO (“Fat Gene”) rs9939609 Hematocrit decreases more dramatically for the AA or AT genotype, compared to the TT genotype, with diet and exercise [181]
G6PD rs1050828 Lower hematocrit with T allele, compared to A allele, for African Americans [182]
GNB3 rs5443 Hematocrit higher with T allele [183]
JAK2 rs12343867





Hematocrit higher with JAK2V617F mutation [184]
ND2 rs28357984 (Mt5178) Higher hematocrit with A allele, compared to C allele [185]

Hematocrit | Encyclopedia.


Normal results

The hematocrit is a test that measures the percentage of blood that is comprised of red blood cells.

The hematocrit is used to screen for anemia, or is measured on a person to determine the extent of anemia. An anemic person has fewer or smaller than normal red blood cells. A low hematocrit, combined with other abnormal blood tests, confirms the diagnosis. The hematocrit is decreased in a variety of common conditions including chronic and recent acute blood loss, some cancers, kidney and liver diseases, malnutrition, vitamin B12 and folic acid deficiencies, irondeficiency, pregnancy, systemic lupus erythematosus, rheumatoid arthritis and peptic ulcer disease. An elevated hematocrit is most often associated with severe burns, diarrhea, shock, Addison’s disease, and dehydration, which is a decreased amount of water in the tissues. These conditions reduce the volume of plasma water causing a relative increase in RBCs, which concentrates the RBCs, called hemoconcentration. An elevated hematocrit may also be caused by an absolute increase in blood cells, called polycythemia. This may be secondary to a decreased amount of oxygen, called hypoxia, or the result of a proliferation of blood forming cells in the bone marrow (polycythemia vera).

Critically high or low levels should be immediately called to the attention of the patient’s nurse or doctor. Transfusion decisions are based on the results of laboratory tests, including the hematocrit. Generally, transfusion is not considered necessary if the hematocrit is above 21%. The hematocrit is also used as a guide to how many transfusions are needed. Each unit of packed red blood cells administered to an adult is expected to increase the hematocrit by approximately 3% to 4%.

Fluid volume in the blood affects hematocrit values. Accordingly, the blood sample should not be taken from an arm receiving IV fluid or during hemodialysis. It should be noted that pregnant women have extra fluid, which dilutes the blood, decreasing the hematocrit. Dehydration concentrates the blood, which increases the hematocrit.

In addition, certain drugs such as penicillin and chloramphenicol may decrease the hematocrit, while glucose levels above 400 mg/dL are known to elevate results. Blood for hematocrit may be collected either by finger puncture, or sticking a needle into a vein, called venipuncture. When performing a finger puncture, the first drop of blood should be wiped away because it dilutes the sample with tissue fluid. A nurse or phlebotomist usually collects the sample following cleaning and disinfecting the skin at the site of the needle stick.


Anemia— A lack of oxygen carrying capacity commonly caused by a decrease in red blood cell number, size, or function.

Dehydration— A decreased amount of water in the tissues.

Hematocrit— The volume of blood occupied by the red blood cells, and expressed in percent.

Hypoxia— A decreased amount of oxygen in the tissues.

Polycythemia— A condition in which the amount of RBCs are increased in the blood.

Blood is made up of red blood cells, white blood cells (WBCs), platelets, and plasma. A decrease in the number or size of red cells also decreases the amount of space they occupy, resulting in a lower hematocrit. Conversely, an increase in the number or size of red cells increases the amount of space they occupy, resulting in a higher hematocrit. Thalassemia minor is an exception in that it usually causes an increase in the number of red blood cells, but because they are small, it results in a decreased hematocrit.

The hematocrit may be measured manually by centrifugation. A thin capillary tube called a microhematocrit tube is filled with blood and sealed at the bottom. The tube is centrifuged at 10,000 RPM (revolutions per minute) for five minutes. The RBCs have the greatest weight and are forced to the bottom of the tube. The WBCs and platelets form a thin layer, called the buffy coat, between the RBCs and the plasma, and the liquid plasma rises to the top. The height of the red cell column is measured as a percent of the total blood column. The higher the column of red cells, the higher the hematocrit. Most commonly, the hematocrit is measured indirectly by an automated blood cell counter. It is important to recognize that different results may be obtained when different measurement principles are used. For example, the microhematocrit tube method will give slightly higher results than the electronic methods when RBCs of abnormal shape are present because more plasma is trapped between the cells.

Discomfort or bruising may occur at the puncture site. Pressure to the puncture site until the bleeding stops reduces bruising; warm packs relieve discomfort. Some people feel dizzy or faint after blood has been drawn, and lying down and relaxing for awhile is helpful for these people.

Other than potential bruising at the puncture site, and/or dizziness, there are no complications associated with this test.

Normal values vary with age and sex. Some representative ranges are:

  • at birth: 42-60%
  • six to 12 months: 33-40%
  • adult males: 42-52%
  • adult females: 35-47%



Chernecky, Cynthia C. and Barbara J. Berger. Laboratory Tests and Diagnostic Procedures. 3rd ed. Philadelphia: W. B. Saunders Company, 2001.

Kee, Joyce LeFever. Handbook of Laboratory and Diagnostic Tests. 4th ed. Upper Saddle River, NJ: Prentice Hall, 2001.

Kjeldsberg, Carl R. Practical Diagnosis of Hematologic Disorders. 3rd ed. Chicago: ASCP Press, 2000.


American Association of Blood Banks. 8101 Glenbrook Road, Bethesda, Maryland 20814. (301) 907-6977. Fax: (301) 907-6895. http://www.aabb.org.

Victoria E. DeMoranville

Mark A. Best

Hematocrit : Nursing2020 Critical Care

Department: Looking at Labs

doi: 10. 1097/01.CCN.0000654816.47865.44



Hematocrit (HCT), also called packed cell volume (PCV), means “to separate blood” and is the packed spun volume of blood that consists of intact red blood cells (RBCs), expressed as a percentage. HCT can be measured directly following centrifugation of a blood sample or calculated using the formula:

HCT = (RBC x MCV)/10. Mean corpuscular volume (MCV) is the average volume (size) of the patient’s RBCs.

HCT is part of the complete blood cell count and indirectly measures the RBC mass. The results are expressed as the percentage by volume of packed RBCs in whole blood (PCV). It is an important measurement in the determination of anemia or polycythemia.

Normal reference values in adults

  • Women: 36% to 48%
  • Men: 42% to 52%.

Clinical alert

An HCT under 20% can lead to heart failure and death; an HCT over 60% is associated with spontaneous thrombosis.

Clinical implications

  • Decreased HCT is an indicator of anemia, a disorder in which there is a reduction in the PCV. An HCT under 30% means that the patient is moderately to severely anemic. Decreased values also occur in the following conditions:
    • – leukemias, lymphomas, Hodgkin disease, myeloproliferative disorders
    • – adrenal insufficiency
    • – chronic disease
    • – acute and chronic blood loss
    • – hemolytic transfusion reactions.
  • The HCT may not be reliable immediately after even a moderate loss of blood or immediately after transfusion.
  • The HCT may be normal immediately after acute hemorrhage. During the recovery phase, both the HCT and the RBC count drop markedly.
  • Usually, the HCT parallels the RBC count when the cells are of normal size. As the number of normal-sized erythrocytes increases, so does the HCT.
    • – However, for the patient with microcytic or macrocytic anemia, this relationship does not hold true.
    • – If a patient has iron-deficiency anemia with small RBCs, the HCT decreases because the microcytic cells pack to a smaller volume. The RBC count, however, may be normal or higher than normal.
  • Increased HCT occurs in:
    • – erythrocytosis
    • – polycythemia vera
    • – hemoconcentration from hypovolemia.

Interfering factors

  • People living at high altitudes have a high HCT.
  • Normally, the HCT slightly decreases in the physiologic hemodilution of pregnancy.
  • The normal values for HCT vary with age and gender. The normal value for infants is higher because the newborn has many macrocytic red cells. The HCT in women is usually slightly lower than in men.
  • There is also a tendency toward a lower HCT in men and women over age 60, corresponding to lower RBC count values in this age group.
  • Severe dehydration from any cause falsely raises the HCT.

Source: Fischbach FT, Fischbach MA. A Manual of Laboratory and Diagnostic Tests. 10th ed. Philadelphia, PA: Wolters Kluwer; 2018.

Wolters Kluwer Health, Inc. All rights reserved.View full article text

a review of different analytical methods


This article describes the advantages and
disadvantages of the different methods of measuring hematocrit
by discussing the following:

  • The components of whole blood
  • Indications for measuring hematocrit
  • Measuring technologies 

    1.  Microhematocrit

    2. Complete blood cell count

    3. Conductivity on blood gas analyzers

    4. Calculation of hematocrit
  • Comparison of the different technologies

This article will be followed by another article describing
the different methods of determining hemoglobin.


Whole blood is comprised of erythrocytes (the red blood cells
or RBCs involved in oxygen transport), platelets and leukocytes
(the white blood cells or WBCs involved in the body’s immune
defense). The cells are suspended in the aqueous medium of

In blood from healthy individuals, erythrocytes
constitute the vast majority of cells; the erythrocytes contain
hemoglobin (Hb), which gives blood its red color and which has
oxygen-binding abilities. Plasma mainly consists of water
(approx. 93 %) but also of salts, various proteins and lipids
as well as other constituents, e.g. glucose.

FIG. 1. A centrifugated whole-blood

The definition of hematocrit (hemato from the Greek haima =
blood; crit from the Greek krinein = to separate) is the ratio
of the volume of packed red blood cells to the total blood
volume and is therefore also known as the packed cell volume,
or PCV. 

The hematocrit is reported as a percentage or a ratio.
In healthy adult individuals the red blood cells constitute
approx. 40-48 %, whereas newborns may have hematocrits of up to
60 % [1]. 

The layer between the RBCs and plasma, the buffy coat
layer, constitutes approx. 1 %. It consists of WBCs and
platelets and should therefore not be calculated as part of the
packed cell volume.

The relationship between hematocrit and

The following is a summary of the quantities/abbreviations that
are relevant when discussing hematocrit:

  • Hct: Hematocrit (% or volume fraction)
  • ctHb: Concentration of total hemoglobin (g/dL,
    g/L or mmol/L)
  • RBC: Red blood cell (erythrocyte) (×
  • MCV: Mean cell volume (fL)
  • MCHC: Mean corpuscular hemoglobin concentration
    (%, g/L or mmol/L)

In normal conditions there is a linear relationship between
hematocrit and the concentration of hemoglobin (ctHb).
An empirical study [2] has shown that the relationship can be
expressed as follows:

Hct (%) = (0.0485 × ctHb (mmol/L) +
0.0083) × 100

Hematocrit can also be estimated from measurements of the
mean cell volume (MCV) or the mean corpuscular hemoglobin
concentration (MCHC):

Hct (%) = MCV × RBC × 0.1

Hct (%) =  
× 100



Hematocrit measurements may be requested when it is suspected
that a patient is anemic or suffering from dehydration,
bleeding or other medical and surgical conditions.

Low hematocrit

A low hematocrit reflects a low number of
circulating red blood cells and is an indicator of a decrease
in the oxygen-carrying capacity or of overhydration. Examples
of conditions causing a low hematocrit (anemia) include

  • Internal or external hemorrhage – bleeding
  • Complication of chronic renal failure – kidney
  • Pernicious anemia – vitamin-B12 deficiency
  • Hemolysis – associated with transfusion reactions

A low hematocrit may be found in autoimmune diseases and
bone-marrow failures.

High hematocrit

A high hematocrit may reflect an absolute increase in the
number of erythrocytes, or a decrease in plasma volume, in
conditions such as [3]:

  • Severe dehydration – e.g. in case of burns, diarrhea or
    excessive use of diuretics
  • Erythrocytosis – excessive red blood cell
  • Polycythemia vera – abnormal increase of blood
  • Hemachromatosis – an inherited iron metabolism

High hematocrit is also used as an indicator of the
excessive intake of exogenous erythropoitin (EPO), which
stimulates the production of red blood cells. Athletes can
artificially improve their performance by enhancing the
oxygen-carrying capacity with EPO.

In newborns and especially premature babies, high hematocrit
values are common. The hematocrit of infants reaches the level
of adult hematocrit by approx. three months of age [1].

The conditions leading to low hematocrit values, e.g.
hemorrhage, often require continuous measurements of the
hematocrit and fast decisions concerning transfusions. If the
hematocrit is measured immediately after an acute hemorrhage,
the value will be normal until the decreased blood volume is
corrected by fluid shifts into the blood vessels.


This section gives a technical description of the most commonly
used techniques for measuring hematocrit:

  1. The determination of hematocrit by means of
  2. The calculation of hematocrit from the complete blood
    cell count (CBC)
  3. The determination of hematocrit by conductivity
  4. The calculation of hematocrit from ctHb

1. Microhematocrit

The reference method recommended by NCCLS of
determining hematocrit or packed cell volume (PCV) is

Method [4]:

Hematocrit (PCV) is the measure of the ratio of the
volume occupied by the red blood cells to the volume of whole
blood. The blood sample is drawn into a capillary and
centrifugated, and then the ratio can be measured and expressed
as a decimal or percentage fraction.


  • Whole blood from a freely flowing skin puncture or
    anticoagulated (EDTA or heparin) venous or arterial
  • Glass capillary tubes with a narrow diameter
  • Sealing compound (if the capillaries are not
  • A microhematocrit centrifuge with a maximum relative
    centrifugal force of 10-15,000 × g, which should be
    reached within 30 seconds [4]
  • Graphic reading device


  • Capillary tubes are filled by capillary forces. A
    minimum of two capillaries is required to ensure balance in
    the centrifuge. It is important that the tubes are sealed
  • After five minutes of centrifugation the hematocrit can
    be measured while the tubes are still kept in a horizontal
    position. A distinct column of packed erythrocytes is
    visible in one end of the capillary tube (Fig. 2). The
    packed erythrocytes are followed by first a small turbid
    layer – the buffy coat layer – and then a clear column of
    plasma (Fig. 2). Hematocrit is estimated by calculating the
    ratio of the column of packed erythrocytes to the total
    length of the sample in the capillary tube, measured with a
    graphic reading device.
  • The measurement should be performed within 10 minutes
    to avoid merging of the layers.

FIG. 2. Reading the hematocrit


  • Studies have shown that spun hematocrit gives values
    approx. 1.5-3.0 % too high due to plasma trapped in the RBC
    layer. If abnormal types of RBCs are present, this bias can
    be even greater, as more plasma is trapped [5]. See also
    Table I.

2. Complete blood cell count (CBC)

In hematology laboratories, automatic cell count
analyzers measuring multiple parameters are the most commonly


The hematocrit is determined indirectly from the
average size and number of RBCs. The reference method is the
Coulter impedance principle [6] and is described below.


  • Sample tubes normally containing 3-5 mL EDTA
    anticoagulated blood


  • The whole-blood sample is diluted automatically with an
    isotonic solution prior to analysis.
  • The diluted blood is forced through an orifice which
    has two electrodes placed on opposite sides (Fig. 3).
  • By applying a constant current between the two
    electrodes, the impedance is constant until a blood cell
    passes through the orifice
  • Due to the non-conductive properties of the red blood
    cell membrane, the electrical resistance increases each
    time an erythrocyte passes through the orifice.
  • The change in potential between the electrodes
    correlates to the volume of the passing erythrocyte.
    Furthermore, erythrocytes that have passed through the
    orifice are counted. From the mean cell volume, the
    erythrocyte count and the dilution factor, the hematocrit
    is derived.

FIG. 3. The Coulter principle


  • When a high reticulocyte or WBC count is present,
    hematocrit determinations using hematology analyzers can
    result in the calculation of falsely elevated values,
    because the higher cell volumes of these cells will
    interfere with the red blood cell count and the calculation
    of the hematocrit [7]. See also Table I.

3. Conductivity on blood gas analyzers

In POCT, blood gas analyzers measuring multiple
STAT parameters are often used. Some blood gas analyzers
determine hematocrit by a conductivity measurement which is
corrected for the concentrations of conducting ions in the


  • Syringes or capillaries containing heparinized arterial
    or venous blood


  • The conductivity is the ability of a solution to
    transmit (conduct) electricity. The electrical current will
    increase in proportion to the number of ions (or charged
    particles) found in a solution, their electrical charge and
    mobility, i.e. how easily the ions can move in the
    solution. The mobility of an ion in a solution will also
    depend on how many cells (and size and shape) are
    suspended in the solution.
  • Both erythrocytes and plasma have characteristic
    electrophysical properties. The membrane of the
    erythrocytes is electrically insulating, mainly due to its
    content of lipids, so that it appears essentially
  • Plasma is fairly conductive due to its content of
    electrolytes and charged proteins; the major contributor to
    plasma conductivity is Na+, the concentration in human
    blood plasma being approx. 140 mmol/L.
  • Due to this, there is an inverse relationship between
    the electrical conductance and the hematocrit in blood when
    the concentration of the charged particles is taken into

Three factors besides the number of RBCs are critical for
the determination of the hematocrit value when using a method
based on measurement of electrical conductivity:

  1. Electrolytes
  2. Temperature
  3. Proteins

Most blood gas analyzers allow for these variables as

  • Concentration of electrolytes: This is determined by
    one or more ion measurements. As sodium is the primary
    electrolyte in plasma, this is the most important ion to
    measure and use in the calculation of hematocrit.
  • A change in the temperature has a significant impact on
    the conductivity because blood has a high temperature
    coefficient. The measuring chamber in blood gas analyzers
    is thermostatted and the blood sample preheated prior to
    measurement; thus there is no contribution from changing
  • The protein concentration in plasma is assumed constant
    in healthy people, so a constant compensation for this is
    incorporated in the calculation of hematocrit on blood gas


  • In patients with abnormal plasma osmolality, e.g.
    patients being treated with plasma expanders, blood
    diluents or massive infusion therapy, the protein
    concentration is no longer constant and the hematocrit
    determination gives falsely low values [8, 9]. Some blood
    gas analyzers offer correction for this bias [10,11,12].
    See also Table I.

4. Calculation of hematocrit from hemoglobin

As there is a linear relationship between
hemoglobin (ctHb) and hematocrit as described earlier,
it is possible to calculate the hematocrit on analyzers that
measure hemoglobin. When making this conversion, two factors
should be taken into consideration:

  • The analytical quality of the ctHb
  • The precision of the equation that converts the two

The measurement of ctHb from most good-quality
analyzers is usually reliable; however, the equations used to
calculate the hematocrit vary from analyzer to analyzer. Some
analyzers use an empirically found equation [2,13] whereas
others use an approximate conversion factor of 3 [14,15].


Hb concentration


Conversion equation

Hct %



Hct (%) = (0.0485 × ctHb (mmol/L) +
0.0083) × 100




Hct (%) = 2.8 × ctHb (g/dL) +




Hct (%) = ctHb (g/dL) / 0.34




Hct (%) = 2.941 × ctHb (g/dL)



TABLE I: Effect of different conversion factors on
Hct %

* Conversion factor: g/dL × 0.62058 = mmol/L


  • It is generally assumed that the conversion from
    hemoglobin to hematocrit is straightforward since most
    methods measuring ctHb are considered to be fairly
    accurate; however, different analyzers use different
    conversion factors, which may compromise the reliability of
    the hematocrit result. Hematocrit and hemoglobin are often
    used interchangeably; however, different studies have shown
    that the two parameters are not comparable, but that they
    have their separate applications [15,17,18,19]. 

Comparing measuring technologies

All measuring technologies for determining hematocrit have
advantages and disadvantages. The following table provides an
easy overview of the described methods. The
advantages/disadvantages listed have all been found by
reviewing the literature, i.e. no prioritizing according to
importance has been done.

Table as word document.




  • Small sample volume
  • Relatively fast analysis
  • Hemolysis detected when result is
  • No dilution needed

Complete blood cell

  • Hct parameter together with other
    hematology parameters – only one blood
    sample is necessary
  • Dilution of sample removes problems
    with hyperosmotic samples
  • No preparation needed
  • No manual dilution needed


  • Small sample volume
  • Short turnaround time
  • Hct parameter together with blood gas,
    pH, electrolytes, and metabolites – only
    one blood sample is necessary
  • No preparation needed
  • No dilution needed
  • Suitable for POCT

Calculation from

  • Hct parameter together with other
    parameters – only one blood sample is
  • Some methods are suitable for POCT

TABLE IIa. Advantages of different methods of
measuring hematocrit.




  • Time-consuming and careful
    preparation required (sealing of
    capillaries, etc)

  • Uncertain manual reading of the

  • Leakage of sealing gives falsely low
    results (more RBCs will be lost than
    plasma) [5]

  • Falsely high Hct readings caused by
    trapped plasma. In normal blood 1.5-3.0
    % [5]

  • In blood with abnormally sized or
    shaped RBCs, more plasma will be
    trapped, causing a higher positive bias
    of Hct

  • Excess EDTA (inadequate blood for
    the fixed amount of EDTA in the tube)
    will cause cell shrinkage and falsely
    lower the Hct [5]

  • Clots will lead to false packing of
    the cells, giving falsely high results

  • Hemolysis will destroy the cell
    walls and lead to false packing of the
    cells, giving falsely low results

  • Acute hyperosmotic conditions will
    change the cell volume and lead to a
    false packing of the cells, giving
    falsely low results [9]

Complete blood cell

  • Elevated reticulocyte or WBC count
    results in falsely high hematocrit
    values because these cells will be
    counted as RBCs [7]

  • Autoagglutination, where two or more
    cells are counted as one, will lead to
    falsely low results [7]

  • Hemolysis will destroy the cell
    walls, giving falsely low results

  • A decreased level of MCV due to
    microcytosis will lead to falsely low
    Hct results, as the RBCs may be
    recognized as leucocytes [7]

  • In patients with abnormal
    osmolality, the addition of an isotonic
    solution may increase the MCV, leading
    to falsely elevated Hct readings

  • Careful sample handling is required,
    especially careful sample mixing, to
    avoid false readings


  • Acute hyperosmotic conditions will
    lead to cell shrinkage as water moves
    out of the cells to equalize the
    osmotic pressure. This will result in
    falsely low results similar to the
    microhematocrit method [9].

  • Variations in protein concentration
    in plasma, e.g. in patients undergoing
    cardiopulmonary bypass where plasma
    dilution with protein-free electrolyte
    solution is necessary, will affect the
    Hct significantly [8,9]. Some analyzers
    offer correction for this bias

  • Arterial blood has approx. 2 %
    higher Hct than venous blood [7]

  • Only heparinized blood can be used

  • Attention must be paid to sample
    handling, specifically proper mixing of
    the sample, to avoid false readings

Calculation from

  • Deviation of MCHC from the standard
    value, e.g. in children, will affect
    the calculated hematocrit [20]

  • Hyperlipemic plasma may falsely
    elevate the hemoglobin [21]

  • An extremely high number of WBCs may
    falsely elevate the hemoglobin [21]

  • Inadequate hemolyzation or mixing of
    the sample will falsely decrease the
    hemoglobin [22]

  • Uncertainty in calculation

TABLE IIb. Disadvantages of different methods of
measuring hematocrit.


When hematocrit is used to assess anemia and the
oxygen-carrying capacity, the advantages and disadvantages of
each method must be carefully considered. In addition, the
specific clinical and analytical needs for any patient
population must be determined.

Hematocrit is traditionally a routine hematology laboratory
parameter; however, measuring hematocrit as a STAT parameter in
a POC setting is in many ways preferable, as this will save
time in critical situations and avoid specimen transport
problems. Some blood gas analyzers offer this possibility,
either by measuring hematocrit by conductivity or by
calculating hematocrit from ctHb. 

Hemoglobin is also used to assess anemia both in the
laboratory and as a STAT parameter on POCT analyzers. Different
hemoglobin measuring methods and their applications will be
discussed in another article.


Both POCT and traditional laboratory methods of measuring or
calculating hematocrit have limitations. Methods used outside
of the laboratory must be intuitive for users without
time-consuming sample handling. 

Methods suitable for an adult
environment may not be suitable for a neonatal environment due
to sample volume limitations. Some methods are not suitable in
certain applications due to e.g. problems associated with
volume expansion fluids or abnormally sized or shaped red blood

These limitations can have important clinical
implications and must be carefully considered as described in
this article.

90,000 Increased hemoglobin – causes of appearance, in what diseases it occurs, diagnostics and methods of treatment


The information in this section cannot be used for self-diagnosis and self-medication. In case of pain or other exacerbation of the disease, only the attending physician should prescribe diagnostic tests. For a diagnosis and correct prescription of treatment, you should contact your doctor.

Increased hemoglobin, or erythrocytosis: causes of occurrence, in what diseases it occurs, diagnosis and treatment methods.


Erythrocytosis – an increase in the content of red cells per unit volume of blood, accompanied by an increase in the level of hemoglobin. The main symptoms of these changes are headaches, muscle pains, dizziness, nosebleeds, fatigue, more specific symptoms depend on the corresponding disease.

Varieties of erythrocytosis

Erythrocytosis can be primary and secondary.

Primary erythrocytosis is considered as an independent disease of the hematopoietic system and has a genetic nature.In medicine, it is known as congenital polycythemia, or Vakez disease. This pathology provokes an increase in bone marrow volume and an increased production of red blood cells and hemoglobin.

Secondary erythrocytosis is not considered a separate disease, but only a symptom of acute or chronic diseases and conditions.
Relative erythrocytosis is a consequence of dehydration caused by profuse diarrhea or vomiting.

Also, an increase in hemoglobin levels can be the result of drug overdose, smoking, alcohol abuse and exposure to chemicals (nitrites).

Absolute erythrocytosis is the result of increased erythropoiesis, the formation of red blood cells in the bone marrow. This form of pathology is always associated with diseases of internal organs or systems.

Possible reasons for the increase in hemoglobin

I. Hereditary:

  1. Changes in the structure of the Jak2 V617F gene, which is responsible for the production of red blood cells.
  2. Inability of blood to bind and transport oxygen to tissues.
  3. Decreased oxygen supply to the kidney tissues (this leads to the fact that they begin to intensively produce the hormone responsible for the formation of red blood cells (erythropoietin)).
  4. Deficiency of enzymes responsible for the production of red blood cells and their function of transporting oxygen to tissues.

II. Acquired:

  1. Kidney disease (hydronephrosis, polycystic kidney disease, cancer and renal artery stenosis).
  2. Diseases of the lungs (chronic obstructive bronchitis, bronchial asthma, diseases affecting the lung tissue, sometimes of unknown cause).
  3. Heart diseases (congenital and acquired heart defects).
  4. Liver diseases (liver tumors).
  5. Diseases of the brain (in particular, cerebellar tumor).
  6. Diseases of the female reproductive system (oncological diseases of the ovaries).
  7. Diseases of the endocrine system, affecting the adrenal glands and contributing to an increase in blood pressure, in which the main drugs used in hypertension (Itsenko-Cushing’s disease, pheochromocytoma) are usually ineffective, as well as diseases of the thyroid gland.
  8. Carbon monoxide poisoning.
  9. Stay at high altitudes.
  10. Obstructive sleep apnea syndrome, characterized by temporary cessation of breathing during sleep.

Which doctor should i contact if hemoglobin is elevated

If an increase in the number of erythrocytes, hematocrit, hemoglobin is detected, first of all, it is necessary to consult a hematologist as soon as possible.

To clarify the diagnosis, a sternal puncture or trepanobiopsy of the bone marrow may be required.

Complete blood count: transcript and norm


What does this mean


Red blood cell count (RBC) Erythrocytes perform the function of supplying oxygen to the tissues of the body, as well as removing carbon dioxide from the tissues, which is then released through the lungs.

If the level of red blood cells is below normal, the body receives insufficient amounts of oxygen.

If the red blood cell count is above normal, there is a high risk that the red blood cells stick together, leading to thrombosis.

4.3-6.2 x 10 at 12 degrees / liter for men

3.8-5.5 x 10 at 12 degrees / liter for women

3.8-5.5 x 10 at 12 degrees / liter for children

Hemoglobin (HGB, Hb) It is a special protein that is responsible for carrying oxygen to organs.

A decrease in hemoglobin levels leads to oxygen starvation of the body.

An increase in hemoglobin levels, as a rule, indicates a high number of red blood cells, or dehydration of the body.

120 – 140 g / l
Hematocrit (HCT) Hematocrit is an indicator that reflects how much blood is occupied by erythrocytes.

Increased hematocrit occurs in erythrocytosis, as well as in dehydration.

A decrease in hematocrit indicates anemia or an increase in the amount of liquid part of the blood.

39 – 49% for men

35 – 45% for women

Red blood cell distribution width (RDWc) The distribution width of red blood cells is an indicator that indicates how much red blood cells differ in size.

If both large and small erythrocytes are present in the blood, this condition is called anisocytosis (this is a sign of iron deficiency, etc.types of anemias).

11.5 – 14.5%
Average erythrocyte volume (MCV) The average red blood cell volume allows the doctor to obtain data on the size of the red blood cell.

Erythrocytes with a small average volume are found in microcytic anemia, iron deficiency anemia, etc.

Erythrocytes with an increased average volume are found in megaloblastic anemia.

80 – 100 fl
Average content of hemoglobin in erythrocyte (MCH) This indicator allows the doctor to determine how much hemoglobin is contained in one red blood cell.

A decrease in this indicator is found in iron deficiency anemia.

Increase – with megaloblastic anemia.

26 – 34 pg (pg)
Average concentration of hemoglobin in erythrocyte (MCHS) The average concentration of hemoglobin in an erythrocyte reflects how much the erythrocyte is saturated with hemoglobin.

A decrease in this indicator is found in iron deficiency anemias, as well as in congenital blood diseases.

There is practically no increase in this indicator.

30 – 370 g / l (g / l)
Number of platelets An increase in the level of platelets in the blood occurs in some blood diseases, as well as after surgery and removal of the spleen.

A decrease in platelet levels occurs in some congenital blood diseases, aplastic anemia, idiopathic thrombocytopenic purpura, liver cirrhosis, etc.

180 – 320 × 109 / l
Leukocyte count (WBC) A high white blood cell count indicates a bacterial infection.

A decrease in the number of leukocytes occurs when taking certain medications, blood diseases, etc.

4.0 – 9.0 × 10 in 9th degree / l
Lymphocyte count (LYM) Lymphocyte is a type of white blood cell that is responsible for the production of immunity and the fight against microbes and viruses.

An increase in the number of lymphocytes occurs in some infectious diseases, as well as in diseases of the blood.

A decrease in the number of lymphocytes occurs in severe chronic diseases, AIDS, renal failure, taking certain drugs that suppress the immune system.

LY% 25-40%

LYM # 1.2 – 3.0×109 / l (or 1.2-63.0 x 103 / μl)

Content of a mixture of monocytes, eosinophils, basophils and immature cells (MID, MXD) These types of blood cells also belong to leukocytes and perform important functions

To determine the nature of changes, as a rule, the percentage of each type of cells is studied.

MID # (MID, MXD #) 0.2-0.8 x 109 / l

MID% (MXD%) 5 – 10%

Granulocyte count (GRA, GRAN) Granulocytes are usually elevated when there is inflammation in the body.

A decrease in the level of granulocytes occurs in aplastic anemia, after taking certain medications, as well as in systemic lupus erythematosus.

GRA # 1.2-6.8 x 109 / L (or 1.2-6.8 x 103 / μL)

GRA% 47 – 72%

Number of monocytes (MON) An increased content of monocytes is found in some infectious diseases, rheumatoid arthritis, blood diseases.

A decrease in the level of monocytes occurs after severe operations, taking drugs that suppress immunity.

MON% 4 – 10%

MON # 0.1-0.7 x 109 / L (or 0.1-0.7 x 103 / μL)

Erythrocyte sedimentation rate , ESR, ESR. An elevated ESR indicates a possible inflammation in the body due to an increased content of inflammatory proteins in the blood. ESR occurs in anemia, malignant tumors, etc.

A decrease in ESR is rare and indicates an increased content of erythrocytes in the blood, or other blood diseases.

Up to 10 mm / h for men

Up to 15 mm / h for women

Hematocrit – CBC

Hematocrit – CBC

Hematocrit: normal, above normal, lowered


Hematocrit is the ratio of the volume of blood cells to plasma.For research, either venous blood is taken, or capillary blood is collected in a special glass capillary treated with heparin.

Age sex Indicator in%
up to 2 weeks 41 – 65
from 2 to 4.3 weeks 33 – 55
4.3 – 8.6 weeks 28 – 42
From 8.6 weeks to 4 months 32 – 44
From 4 to 6 months 31 – 41
6 to 9 months 32 – 40
9 to 12 months 33 – 41
1 to 3 years 32 – 40
3 to 6 years 32 – 42
6 to 9 years 33 – 41
9 to 12 years 34 – 43
12 to 15 years women 34 – 44
men 35 – 45
From 15 to 18 years old women 34 – 44
men 37 – 48
From 18 to 45 years old women 38 – 47
men 42 – 50
From 45 to 65 years old women 35 – 47
men 39 – 50
after 65 years women 35 – 47
men 37 – 51

• male hematocrit – 41-53%;
• female hematocrit – 36–46%;
• hematocrit of newborns – 54–68%.

Reasons for an increase in hematocrit
  • loss of fluid and thickening of the blood with repeated vomiting or severe diarrhea (diarrhea),
  • erythremia,
  • dehydration,
  • burn disease,
  • peritonitis,
  • neoplasms of the kidneys, accompanied by increased eropoetin
  • polycystic and renal hydronephrosis;
Reasons for a decrease in hematocrit
  • blood loss,
  • massive traumatic injuries,
  • starvation,
  • blood thinning (hemodilution) as a result of active intravenous fluids,
  • pregnancy (especially the second half),
  • excess protein in plasma (hyperproteinemia)

Blood test


MCH – meancorpuscular hemoglobin.This index reflects the absolute content of hemoglobin in one erythrocyte in picograms (pg). MCH is calculated by the formula:

MCH = hemoglobin (g / l) / erythrocyte count = pg

Norm MCH
24 – 33 pg.

Blood test


MCHC – meancorpuscular hemoglobin concentration. This index reflects the degree of saturation of the erythrocyte with hemoglobin and is expressed in%. That is, according to this index, one can say how many percent is the hemoglobin content in one erythrocyte.MCSU is calculated as follows:
MCSU = (hemoglobin (g / l) / hematocrit (%)) * 10 =%
30 – 38%

Blood test


MCV – meancorpuscular volume. This indicator reflects the average volume of erythrocytes, expressed in cubic microns (microns 3 ) or femtoliters (fl). Calculate MCV by the formula:
MCV = hematocrit (%) * 10 / number of erythrocytes (T / L) = μm 3 (fl)

Norm MCV
80-95 microns 3 (fl)

General blood test

General blood test of the child: hemoglobin, hematocrit, reticulocytes

Taking our child for a general blood test, we get a piece of paper with a fairly large number of different numbers and words that the vast majority of us do not say anything at all.In this article, we want to talk about such indicators as: hemoglobin, hematocrit and reculocytes, which relate to one of the three formed elements – erythrocytes. We will start with them, and then we will go in order.

Erythrocytes in the general blood test of a child

In the article “General blood test of a child – basic concepts” it was said that red blood cells are one of the formed elements, but, in fact, they are the main cells. Their number is the largest in comparison with others, but conducting a general analysis implies determining their exact number in one liter.For this, a clearly measured, but very small, volume of blood is taken, placed in a special vessel and the number of these cells is counted under a microscope. After that, in proportion, the result is converted to an indicator per liter. The last number always has 12 zeros, and the result of the analysis is the number in front of them.

An increased level of erythrocytes, like hemoglobin, which will be discussed below, is possible in very rare diseases of the entire hematopoietic system. Most often, he says that this tissue thickens in the body, which is a consequence of a lack of fluid, and this happens with diarrhea, with vomiting, excessive sweating, etc.

A lowered level is an unambiguous sign of anemia, which is the result of:

  • violation of the “reproduction” of erythrocytes or their destruction for any reason;
  • blood loss.

Hemoglobin in the general analysis of the child’s blood

Hemoglobin itself, also referred to as Hb, is a protein, but special. Its peculiarity lies in the easy ability to connect and part with any gases. Oxygen is a gas and it is hemoglobin that combines with it in the lungs, then delivers it to the tissues of the body, gives it up there, combines with carbon dioxide, delivers it to the lungs, and again everything is repeated anew.By the way, it is in hemoglobin that the component that gives the red tint is contained. It is called gem.

The hemoglobin content in the results of a general blood test of a child is measured in grams per liter (g / l), i.e. expresses the total number of grams in one liter.

For children, unlike adults, the hemoglobin content is the same for both girls and boys. But right there it is worth noting that a newborn’s hemoglobin and erythrocyte count will always be elevated.This is normal and after birth begins the breakdown of the “excess” of erythrocytes, which lasts approximately 2-3 weeks.

Average hemoglobin content in an erythrocyte, color index

When calculating an indicator of hemoglobin content in an erythrocyte, the norm of which is considered to be a level of 30 – 35 pg 2 , the amount of hemoglobin in one liter is simply taken and divided by the number of red blood cells in the same liter …

In approximately the same way, but according to a more complex formula, taking into account the indicator of the norm, the color indicator is calculated.The norm for him is one, i.e. the number of erythrocytes and hemoglobin should be exactly equal to the accepted level as the norm.

Hematocrit in the general analysis of the child’s blood

The hematocrit indicator (also referred to as Ht) is one of the most informative and very important in the general analysis of the child’s blood. It reflects the ratio of the volumes of plasma and shaped elements. You can read more about the first and second concepts in the article “General blood count of a child – the main points.”Such a definition may seem too complicated and it is better to explain it using an example that is clear to everyone.

Let’s imagine a jar (let it be a liter) with the most common compote made from any berry. In our example, it will mean a liter of blood. So the liquid in our jar is plasma, and the berries floating in it are shaped elements. Compote can be different in its density and it depends on the number of berries floating in it. The more of them, the thicker the compote and this density, only in relation to our topic of conversation, reflects the hematocrit indicator.By its growth, thickening is determined, and by its decrease, conclusions are drawn about liquefaction.

Reticulocytes in the general analysis of the child’s blood

Reculocytes are the same erythrocytes (they are also mentioned in the article “General analysis of the child’s blood – highlights”), but only young. Their presence does not indicate an illness – they are always there. Their appearance is a constant process, but the number of reticulocytes is determined by the body’s need for new erythrocytes. The number of reticulocytes is measured in ppm, expressing a thousandth of a specific total.

Attention !!!

Before comparing the results of your child’s general blood test with the average for red blood cells and shown in the table below, we want to note that an increase in the level of hematocrit, hemoglobin and red blood cells occurs when the blood clots, and this is a consequence of the loss of fluid in the body. In other words, if there is vomiting, diarrhea, general overheating of the body, excessive sweating, etc., leading to the withdrawal of fluid, then thickening and, consequently, an increase in indicators will occur.

You can read about the reliability of materials related to the child’s health by clicking on the link provided.

You can find more materials on child health in the section of the same name of our parents’ club by clicking on the link given, as well as in its subsection “Guide for parents”.

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08/27/2020 90,000 Hematocrit in a child is increased – what does this mean in diagnosis?

If you look closely at the blood test, it can be noted that it indicates the hematocrit number.The hematocrit level indicates how many red cells, called red blood cells, are in the blood. They play a major role in the human body, since, first of all, they enrich all tissues with oxygen and various nutrients.

When the results of the analysis show that the hematocrit is increased, then, most likely, there are abnormalities in the work of the body. A lowered hematocrit is practically not dangerous, in contrast to an increased hematocrit, so it is worth taking a closer look at the latest changes in the blood.For the attending physician, a blood test is important, since he will be able to determine not only the presence of the disease, but also the severity of its course.

Why and how the analysis is performed

So, the hematocrit number can be calculated from a blood test. For this, blood is drawn into a special test tube from a glass and its centrifugation begins for a certain time. As a rule, as a result of this, heavy elements descend (namely, erythrocytes), and the plasma floats upward.

There are divisions on the test tube, by which the number of red cells in the body is determined. When an increased or decreased hematocrit is detected, the interpretation of the analysis is recorded as a percentage. Such an analysis is done in a conventional clinical laboratory.

The norm in a child

Throughout life, the norm of hematocrit in a person can change, this is especially noticeable in childhood:

  1. In a child who is just born, the norm can be from 45% to 63%.
  2. Up to three months old, this level decreases slightly in a baby and reaches a maximum of 44%.
  3. Before one year, the hematocrit level should drop to 35%.
  4. Up to ten years old, the child’s hematocrit should not exceed 34%.

What does the deviation from the norm say

When a child’s hematocrit is increased, then parents should pay attention to this problem, as this usually indicates a serious illness, although sometimes it is associated with physiological changes.

If the hematocrit rises, then the child’s blood becomes thick and viscous. This is due to the fact that the number of red blood cells increases. This condition can be dangerous for any person, because it can provoke blood clots.

Some parents worry and ask the question – if the hematocrit is increased, what does it mean, and how should it be normalized? But we must remember that if an increase occurs by 10% in a child under one year old, then most likely the reason is hidden in the physiological development of the baby, and there is no reason for worry.

Symptoms in case of abnormalities

If the hematocrit of a teenager is low, it can lead to serious health problems. As a result of the reduced number of red blood cells, the amount of oxygen supplied to the organs is reduced, and this, in turn, leads to a violation of the acid-base balance.

As a result of this, the child feels weak, begins to get tired quickly, he has complaints of rapid heartbeat and shortness of breath. Also, a teenager may complain of constant dizziness, and in some cases, he may develop nausea.

Only a doctor will be able to establish the exact reason why this is happening, he will also prescribe medications that can restore the hematocrit level.

Reasons why the hematocrit may increase

It may turn out that the hematocrit is increased in a teenager or baby if the analysis was not collected correctly. For example, a child did not drink water for a long time before donating blood. In this case, it can become thick. The same happens when the baby’s body as a result of an illness suffers from dehydration due to poisoning and vomiting or at high body temperature.

An increase in hematocrit may be associated with pathological conditions that have caused an increase in the concentration of red blood cells. That is, when the child’s hematocrit is increased, the reasons may be hidden in the following ailments:

  1. Kidney disease, which can be congenital or acquired during life. This includes polycystic disease, the development of neoplasms, and hydronephrosis.
  2. Pathology in the respiratory system, inflammation in the lungs and bronchi.
  3. Injuries and various degrees of burns.
  4. Heart disease. They can be congenital, or they can be acquired due to heavy physical exertion.
  5. Blood problems. Leukemia.
  6. Problems in the gastrointestinal tract.
  7. Asymptomatic oxygen starvation.
  8. Taking certain medications for a long time (not only antibiotics can lead to an increase in hematocrit).

Only a doctor can determine the exact cause. Based on the results of the analysis, he will offer other diagnostic methods to identify the disease that led to an increase in the child’s hematocrit.

What is the risk of increased hematocrit in children

If the hematocrit in a child is increased, then this leads to thickening of the blood, which subsequently leads to the formation of blood clots. And, as we have already mentioned, the described phenomenon can be a consequence of serious diseases associated with the circulatory system, the formation of tumors, both benign and malignant, with an inflammatory process in the adrenal glands, lungs and kidneys. An increase in the volume of erythrocytes is also manifested in peritonitis.Although the hematocrit can increase on its own if the child is high in the mountains, as well as if he is exposed to sunlight for a long time.

How to treat an increased hematocrit in a child

Some parents immediately start to panic if they find out from a doctor that a child has an increased hematocrit. What does it mean? Do not worry right away, in order to accurately establish the cause of the deviations, the doctor will offer to carry out another whole chain of tests. And as soon as the cause is established, treatment will be prescribed if necessary.

First of all, in such cases, it is recommended that the patient provide proper nutrition, which includes a large amount of fortified food. If you follow all the doctor’s prescriptions, then soon the normal level of red blood cells will be restored.

The doctor will accurately reveal how much the child’s hematocrit is increased, and if these indicators are insignificant, and the results of other tests do not show any abnormalities, then this may be due to physiological development.

When changes in hematocrit are not dangerous for the child’s health

As we have already said, high hematocrit is not always associated with pathologies, sometimes it is just a temporary phenomenon. For example, if a person drinks little water per day, then, as a result, the blood may thicken. Therefore, experts recommend that parents monitor the regime and nutrition of their baby. After all, if you eliminate the primary problems, then soon the blood will return to normal. And it is recommended to take tests not once, but several times, with a short break.

It should be noted that children who live in the mountains, due to lack of oxygen, constantly suffer from increased hematocrit, but they gradually adapt, therefore, as a rule, such an increase does not have any consequences for the body.

If the child’s hematocrit is increased, then you should definitely pay attention to the problem in order to exclude possible serious diseases that can be prevented if treatment is started on time. A child with a high hematocrit will complain of frequent dizziness and even nausea.It is often possible to observe in him a state of “daze”, shortness of breath and numbness of the limbs.

How quickly the hematocrit recovers will depend on what caused it to rise. For example, if a child received a burn, then the described indicator will normalize after the healing process begins, but if the reason is hidden in other, more serious diseases, then the body should be fully examined and drug treatment should be carried out.

What do the indicators of erythrocytes MCV, MCH, MCHC in the blood test say?

What do the indicators of erythrocytes MCV, MCH, MCHC in the blood test say?

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What do the erythrocyte counts in the blood test say?
What are the RBC, MCV, MCH, MCHC erythrocyte counts?

Indicators of erythrocytes (RBC – Red Blood Cells, literally – red blood cells) are separate components of the clinical (general, morphological) blood test, which is also called “complete blood count” or “Complete Blood Count” (CBC ) . CBC is performed to determine the number of different types of cells found in a patient’s blood and their physical characteristics.

Blood consists of erythrocytes, leukocytes and platelets, which are suspended in plasma. Platelets are cells that provide blood clots and protect the body from blood loss if injured. Red blood cells (RBC) contain the protein hemoglobin, which carries oxygen throughout the body, to all tissues and organs.Red blood cells are pale red in color due to hemoglobin. The shape of the erythrocyte resembles a donut, but instead of a hole in the middle, it has a thinning. In a normal state, all red blood cells in the blood are basically the same color, size, and shape. However, certain conditions can lead to changes that impair their ability to function properly. For example, Anemia .

Anemia is a common blood disorder characterized by too few, deformed or poorly functioning red blood cells.

RBC values ​​determined in the laboratory indicate the size, shape and physical characteristics of RBCs. Your veterinarian can use red blood cell counts to diagnose the causes of anemia.

What are the indicators of erythrocytes MCV, MCH, MCHC for in the blood test ?

Indicators of erythrocytes and their number are used to diagnose various types of anemia. If, as a result of a clinical blood test, it turns out that the patient has too low an indicator of the number of red blood cells or their characteristics differ from the norm, we can talk about some kind of anemia.

Anemia is a condition in which the number of red blood cells or the amount of hemoglobin in the blood falls below normal levels. This impairs gas exchange of tissues throughout the body, causing a lack of oxygen in the organs. With various degrees of anemia, the animal feels unwell, tired, dizzy, there is a desire to take a break, and shortness of breath may occur. Symptoms can be accompanied by other abnormalities if the body does not receive enough oxygen to function normally.

What are the causes of anemia in animals?

Anemia can occur if:

  • too few red blood cells are created, which is called aplastic anemia;
  • 90,034 red blood cells are destroyed prematurely, which is called hemolytic anemia;

  • significant blood loss occurs, e.g. hemorrhage

Anemia can occur for a variety of reasons:

  • Anemia can be inherited.This means that the genetic condition is passed from parents to children through their genes;
  • Anemia can develop suddenly at any time in the patient’s life;
  • Anemia can be acute, meaning it develops over a short period of time;
  • Anemia can also be chronic, that is, it develops and persists for, for example, several months

Possible immediate causes of anemia:

  • diets not containing iron, vitamin B-12, folate or folic acid;
  • chronic diseases such as cancer (malignant neoplasms), diabetes, inflammatory bowel disease, kidney disease or thyroiditis, which is an inflammation of the thyroid gland;
  • chronic infections such as viral immunodeficiency of cats, tuberculosis or others;
  • significant blood loss or hemorrhage;
  • Diseases affecting the bone marrow such as leukemia (feline viral leukemia), lymphoma or multiple myeloma
  • chemotherapy;
  • lead poisoning;
  • pregnancy;
  • Certain genetic diseases, such as thalassemia, which is a hereditary form of anemia or sickle cell anemia that occurs when red blood cells cannot carry oxygen well and are sickle-shaped

Iron deficiency anemia is the most common type of anemia.

Symptoms of anemia can be very mild at first. For example, many patients do not even notice that they are anemic. The most common early symptoms of anemia are:

  • fatigue;
  • lack of energy;
  • weakness;
  • pale skin

As the disease progresses, new symptoms may appear:

  • dizziness;
  • Feeling of coldness or numbness in the limbs;
  • 90,034 shortness of breath;

  • irregular or fast heartbeat;
  • 90,034 chest pain;

  • headaches

In human medicine, most patients do not know they have anemia until they have a complete clinical blood count (CBC) blood test and find abnormalities.

CBC (Complete Blood Count) is a broad set of parameters that measures the number of all red blood cells, white blood cells and platelets in a blood sample. If the animal is found to be anemic, CBC readings can help determine what is causing the anemia.

What happens during a CBC?

A small amount of blood must be drawn from the patient to test for RBC indices. Your animal does not need any special preparations for this test, unlike a biochemical test, where a blood sample is taken on an empty stomach after a fasting diet for 6-8 hours.

Next, we describe what happens during CBC:

If blood is drawn from a vein, the veterinarian or assistant will first cleanse the area near the vein from hair, treat it with an antiseptic, and apply a tourniquet above the sampling site so that the vein fills with more blood.

An experienced veterinarian carefully inserts a needle into a vein and slowly draws blood from the bloodstream into a syringe or tube. An intravenous catheter is sometimes used.

When the required amount of blood has been taken, the veterinarian removes the tourniquet, removes the needle and, in some cases, puts a compress over the blood sampling site to exclude the formation of a hematoma.

Then the blood sample is sent to the laboratory for analysis, where laboratory personnel are analyzed using special equipment. It should be borne in mind that a clinical blood test, if it is performed using the old methods using a microscope, gives only an approximate idea of ​​the patient’s condition, since it has a large error. In addition, the calculation of the hemoglobin concentration, CBC and parameters such as MCV, MCH, MCHC manually is generally not possible in practice.

In the laboratory of the Kotofey veterinary clinic, a complete CBC blood cell count is performed using an automatic computer-controlled analyzer, which ensures high accuracy and stability of the results.

What are the three main indicators of erythrocyte indices?

Erythrocyte indices have three main indicators:

  • mean body volume (MCV) , which shows the mean size of red blood cells;
  • average corpuscular hemoglobin (MCH) , which indicates the average amount of hemoglobin per erythrocyte;
  • mean corpuscular hemoglobin concentration (MCHC) , which is the amount of hemoglobin relative to the size of the concentration of red blood cells, or hemoglobin per red blood cell

The norms for the indicators of the clinical analysis of blood not only may differ depending on the types of patients (cats, dogs, etc.)but should also be taken into account by laboratory equipment and personnel when performing the analysis. Therefore, the CBC blood test in animals must be performed in specialized veterinary laboratories. It is for this reason that veterinary clinics that use the services of human medicine laboratories in many cases receive incorrect results.

Normal value ranges may vary slightly from laboratory to laboratory.

What do the results of the erythrocyte indices mean?

CBC RBC Index can help your doctor determine the cause of anemia in your animal.MCV is the most useful CBC score and helps determine the type of anemia.

If the veterinarian sees a low, normal, or high MCV, this will help determine the cause of the anemia.

MCV High

If the MCV is higher than normal, this indicates that there are more red blood cells than usual. This is called macrocytic anemia .

Macrocytic anemia can be caused by the following reasons:

  • vitamin B12 deficiency;
  • folate deficiency;
  • chemotherapy;
  • pre-leukemic condition


MCV will be below normal if red blood cells are too small.This condition is called microcytic anemia .

Microcytic anemia can be caused by the following reasons:

  • iron deficiency, which may be caused by poor dietary iron intake, gastrointestinal or other bleeding;
  • thalassemia;
  • lead poisoning;
  • chronic diseases

Normal level MCV

Normal MCV means the patient’s red blood cells are of normal size.A normal MCV can also be accompanied by anemia, for example, if red blood cells are normal in size but too few, or if other RBC readings are abnormal. This is called normocytic anemia .

Normocytic anemia occurs when red blood cells are of normal size and hemoglobin, but there are too few of them.

This may be due to the following reasons:

  • sudden and significant blood loss;
  • cardiac problems;
  • tumor;
  • Chronic disease such as kidney disease or endocrine disorder;
  • aplastic anemia;
  • blood infection


If a patient has a high MCHC, it means that the relative concentration of hemoglobin per erythrocyte is high.MCHC may be elevated in diseases such as:

  • hereditary spherocytosis;
  • sickle cell anemia;
  • homozygous hemoglobin C disease

Low level MCHC

If a patient has a low MCHC level, this means that the relative concentration of hemoglobin per red blood cell is low. Red blood cells appear lighter in color when viewed under a microscope. This is called hypochromia .Patients with anemia and a corresponding low MCHC are called hypochromic .

Causes that can cause a low MCHC include the same causes that cause a low MCV, including:

  • iron deficiency;
  • 90,034 chronic diseases;

  • thalassemia;
  • lead poisoning

Generally, low MCV and MCHC are found together. Anemias in which both MCV and MCHC are low are termed microcytic hypochromic anemia .


The veterinarian may also perform other diagnostic tests. Treatment for any anemia depends on the underlying cause. For example, if anemia is caused by an iron deficiency, your doctor may advise you to take iron supplements or change a diet that contains more iron supplements. If a patient has an underlying medical condition that causes anemia, treatment for that condition can often also reduce the degree of anemia.

We recommend that you consult with your veterinarian if your animal has any symptoms of anemia or if you have any concerns about the CBC or RBC results.

You can take a CBC blood test with erythrocyte indices RBC, MCV, MCH, MCHC in the city of Dnipro in the independent laboratory of the Kotofey veterinary clinic.

The article was written using materials that are in the public domain.
When writing the article, foreign literature was used.

90,000 Hematocrit increased – what does it mean in a child, man and woman, the main causes and their elimination

Blood is composed of many structural elements.They are responsible for carrying oxygen, nutrients and hormones between different systems. In some people, during a general blood test, it is revealed that the hematocrit is increased – what this means and whether a change in this indicator is dangerous for the body, you will learn from the information below.

Related Articles

What is hematocrit

Erythrocytes are an important constituent of blood. They are responsible for carrying oxygen throughout the body. Hematocrit is a measure of the number of red blood cells in the blood.Its fluctuation to a smaller or larger side indicates that the human body has been exposed to some kind of disease. In some clinics, hct means the volume of all formed elements to the volume of blood.

Norm of hematocrit

A blood viscosity test is prescribed for people who have pronounced symptoms of dehydration, severe vomiting due to poisoning, or diarrhea. The biological indicators are influenced by the age and gender of a person. Doctors have a special formula used to establish the hematocrit number.It is calculated as follows:

  1. Determine the content of erythrocytes as a percentage or fractional component.
  2. The result is multiplied by 0.001.

High hematocrit in newborns is considered normal. The value of this indicator is 20-30% higher than that of adults. Then the number of red blood cells drops sharply. It is considered normal when the value of the hematocrit in the blood is 40-45%. In pregnant women, the number of red blood cells begins to decrease from the 20th week, and then returns to normal after childbirth.Sometimes the hematocrit is the number of leukocytes, platelets and erythrocytes. The number of the latter elements prevails in the blood.

For women

Interpretation of blood tests is carried out taking into account the age and state of health of the patients:

  • For young women under 30, the indicator should not exceed 43%.
  • After 35 years, a value of 44-46% is considered normal.
  • During pregnancy, the rate decreases to 35-40%.This fluctuation in indicators is due to the fact that the fetus begins to actively develop.

For children

At birth in babies, the hematocrit rate reaches 60-65%. Blood sampling for determination is carried out from the umbilical cord. At 2 weeks, this figure decreases to 56%. Mild erythrocytosis persists for up to 1 month. The hematocrit at this time reaches 50%. Closer to the year, the figure decreases to 40%. In adolescents aged 12-13, regardless of gender, the ratio of erythrocytes to plasma should not be more than 41%.

For men

Gender influences the amount of hormones in the body. In men, the amount of estrogen in the body is lower, so the blood is thicker, and blood vessels are prone to blood clots. Standards:

  • In boys under 20 years of age, the hematocrit should not exceed 48%.
  • From 20 to 50 years old, a value equal to 46-49% is considered normal.
  • After 50 years, an increase of up to 49.5% is permissible.

What does the increased hematocrit in the blood mean

This condition is characterized by a large accumulation of red blood cells in the fluid.The concentration of this component can vary in 2 cases. The first is accompanied by an increase in the erythrocyte mass, and the second is characterized by a decrease in the liquid part of the blood. In both situations, this deviation increases the risk of thrombosis and other vascular damage.

There is an increase in hematocrit with dizziness. In large quantities, red blood cells are able to carry an increased amount of oxygen throughout the body, and this leads to mild poisoning. If the level of red blood cells is not lowered, the disease will progress.The person will be:

  1. Feel nauseous
  2. notice numbness in the limbs;
  3. have trouble breathing.

Hematocrit increased in an adult

The main function of red blood cells is to carry oxygen. If their number changes upwards, it means that the transmission capacity of these components increases. This condition can be provoked by hypoxia or dehydration. This condition can be normal in people who lead a sedentary lifestyle.If the hematocrit is increased in an adult, this may indicate:

  • Chronic lung diseases. May be caused by smoking, bronchitis, or tuberculosis.
  • Diseases of the hormonal system, accompanied by increased production of androgens.
  • Cancer diseases.
  • Renal disease, when the process of fluid absorption is impaired.
  • Heart failure.
  • Inflammation of the abdominal cavity.
Increased hematocrit in women

There is an increase in the number of red blood cells in the 3rd trimester of pregnancy. The body begins to actively store water and nutrients, which is considered beneficial for the developing fetus. A similar picture can occur if a woman has any malignant or benign formation. For further diagnosis, the patient is referred for an ultrasound of the abdominal organs. A slight increase in hematocrit is considered normal if a woman is taking COCs or has started menstruating.

Hematocrit increased in a child

A change in this indicator can indicate all kinds of chronic or acute pathological processes. An increased hematocrit in the blood of a child in 70% indicates renal pathology. In some babies, the number of red blood cells can change with oxygen deprivation or leukemia. The doctor should be engaged in identifying the reasons that provoked a change in the composition of the blood.

Reasons for an increase in hematocrit in the blood

The change in this indicator can be physiological or clinical, i.e.e. under the influence of disease. If the hematocrit in the blood of a healthy person is increased, then in 90% of cases this is due to the body’s attempt to adapt to changing environmental conditions. If the ratio of plasma and red blood cells changes after surgery, then a pathological inflammatory process has begun in some organ.

For an adult

The body always tries to keep all internal processes in balance, therefore, with an increase or decrease in any elements in the blood, compensating mechanisms are activated.All systems are trying to adapt to new living conditions, which is accompanied by the manifestation of certain symptoms. For example, when the body lacks iron or vitamin B12, anemia develops, and the number of red blood cells can, on the contrary, drop to 15-25%.

The most common causes of an increase in hematocrit in adults are:

  • Water deficiency in the body. This leads to a decrease in the amount of plasma and an increase in the number of red blood cells. Vomiting, diarrhea, and insufficient water intake can provoke the development of this condition.The body has to take fluid from the blood. To lower your hematocrit, you need to drink more fluids.
  • Chronic hypoxia. It occurs in people who have diabetes or who smoke frequently. Increased hematocrit in men is diagnosed in 70% of cases for this reason.
  • Diseases provoking a decrease in blood plasma. Second-degree skin burns, pathological manifestations of peritonitis and polycystic disease are accompanied by a decrease in the amount of circulating fluid in the body.
  • Kidney disease. Acute or chronic forms of hydronephrosis, polycystic diseases lead to increased production of the hormone erythropoietin. The consequence of this condition is a decrease in plasma and general dehydration.
  • Taking medications for a long time.

For a child

In childhood, a slight increase in hematocrit (10-15%) is considered normal. It indicates the physiological processes in the body. When the baby reaches 1 year old, the number of erythrocytes should return to normal.If the hematocrit continues to be high, a diagnosis is necessary. The reasons for the change in this indicator in children are as follows:

  • chronic and acquired renal ailments;
  • diseases of the respiratory organs;
  • cardiac pathologies;
  • external and internal injuries.

What can affect the norm of hematocrit

An increase or decrease in the number of red blood cells can cause more than serious illness or exposure to traumatic factors such as burns.In people who like to smoke, the hematocrit is higher than normal, because the process of inhaling tobacco provokes oxygen starvation of tissues. The patient may not even be aware that his body is in a state of constant stress. The hematocrit rate may change for the following reasons:

  • Continuous or intermittent work at height. The influence of this factor affects residents of high mountain areas and climbers.
  • Taking anabolic steroids, which provoke muscle growth, lowers hemoglobin.As a result, the hematocrit number decreases.

Video: blood hematocrit

Determination of hematocrit number
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Attention! The information presented in the article is for informational purposes only. The materials of the article do not call for self-treatment. Only a qualified doctor can diagnose and give recommendations for treatment, based on the individual characteristics of a particular patient.