What is a hematocrit test. How is the hematocrit test performed. What are normal hematocrit levels for adults and infants. What can cause high or low hematocrit levels. How does hematocrit relate to overall health.

Understanding the Hematocrit Test: A Crucial Blood Measurement

The hematocrit test is a fundamental component of blood analysis that measures the proportion of red blood cells in a person’s blood volume. This essential diagnostic tool provides valuable insights into an individual’s overall health and can help identify various medical conditions.

To fully grasp the significance of the hematocrit test, it’s crucial to understand its role in assessing blood composition. How does the hematocrit test work? The test calculates the percentage of blood volume occupied by red blood cells, taking into account both their number and size. This information is vital for healthcare providers in evaluating a patient’s blood health and detecting potential abnormalities.

The Importance of Red Blood Cells in Body Function

Red blood cells play a critical role in maintaining proper bodily functions. What are the primary functions of red blood cells? These cells are responsible for:

• Transporting oxygen and nutrients to body tissues
• Removing waste products and carbon dioxide
• Distributing hormones from endocrine organs to target tissues
• Maintaining body temperature and pH levels
• Contributing to the body’s protective functions, including clot formation and infection prevention

Given their crucial role, any imbalance in red blood cell levels can have significant implications for overall health and well-being.

The Hematocrit Test Procedure: What to Expect

Understanding the hematocrit test procedure can help alleviate any concerns patients may have about the process. How is the hematocrit test performed? The test requires a blood sample, which is typically obtained through a simple blood draw.

Preparation and Experience

One of the advantages of the hematocrit test is that it requires no special preparation on the part of the patient. What should you expect during the blood draw? While experiences may vary, most people report feeling a brief prick or sting when the needle is inserted. Some individuals may experience moderate pain, but this sensation usually subsides quickly.

After the blood draw, patients might notice some throbbing or a slight bruise at the insertion site. These minor side effects typically resolve on their own within a short period.

Reasons for Conducting a Hematocrit Test

Healthcare providers may recommend a hematocrit test for various reasons. When might a doctor order this test? Common scenarios include:

• Screening for anemia or other blood disorders
• Evaluating overall health, especially in patients with chronic medical conditions
• Monitoring during pregnancy
• Assessing blood loss before and after major surgeries
• Investigating unexplained symptoms such as fatigue, weight loss, or difficulty concentrating
• Monitoring the effects of certain medications or treatments, particularly those that may affect blood cell production

The hematocrit test is typically performed as part of a complete blood count (CBC), which provides a comprehensive overview of blood cell composition and characteristics.

Interpreting Hematocrit Test Results: Normal Ranges and Implications

Understanding hematocrit test results is crucial for both healthcare providers and patients. What are considered normal hematocrit levels? Normal ranges can vary slightly between laboratories, but general guidelines are as follows:

• Adult males: 40.7% to 50.3%
• Adult females: 36.1% to 44.3%
• Newborns: 45% to 61%
• Infants: 32% to 42%

It’s important to note that these ranges are general guidelines, and individual results should always be interpreted in the context of a patient’s overall health and medical history.

Abnormal Hematocrit Levels: Causes and Implications

Deviations from the normal hematocrit range can indicate various health issues. What can cause low hematocrit levels? Some common causes include:

• Anemia
• Bleeding or blood loss
• Bone marrow disorders affecting red blood cell production
• Chronic illnesses, including kidney disease
• Nutritional deficiencies, particularly iron, folate, vitamin B12, and vitamin B6
• Leukemia and other cancers
• Hemolysis (destruction of red blood cells)

On the other hand, high hematocrit levels can also indicate potential health concerns. What conditions are associated with elevated hematocrit? Some possibilities include:

• Dehydration
• Polycythemia vera (a bone marrow disorder causing overproduction of red blood cells)
• Chronic lung diseases
• Congenital heart defects
• Living at high altitudes
• Certain medications or performance-enhancing drugs

The Impact of Hematocrit Levels on Overall Health

Hematocrit levels can significantly influence an individual’s overall health and well-being. How do abnormal hematocrit levels affect the body? Both high and low levels can lead to various symptoms and complications:

Effects of Low Hematocrit

Low hematocrit levels, often associated with anemia, can result in:

• Fatigue and weakness
• Shortness of breath
• Dizziness
• Pale skin
• Rapid heartbeat
• Difficulty concentrating

Consequences of High Hematocrit

Elevated hematocrit levels may lead to:

• Increased risk of blood clots
• Headaches
• Vision problems
• Itching
• Reddened skin
• Joint pain

Understanding these potential effects underscores the importance of maintaining healthy hematocrit levels through proper medical care and lifestyle choices.

Factors Influencing Hematocrit Levels: Beyond Medical Conditions

While various medical conditions can affect hematocrit levels, several other factors can influence test results. What external factors can impact hematocrit? Consider the following:

• Altitude: Living at high altitudes can naturally increase hematocrit levels as the body adapts to lower oxygen levels.
• Hydration status: Dehydration can temporarily elevate hematocrit, while overhydration may lower it.
• Physical activity: Intense exercise can cause short-term fluctuations in hematocrit levels.
• Smoking: Tobacco use can artificially elevate hematocrit levels.
• Pregnancy: Hematocrit levels typically decrease during pregnancy due to increased blood volume.
• Medications: Certain drugs, such as diuretics or erythropoiesis-stimulating agents, can affect hematocrit.

Healthcare providers take these factors into account when interpreting hematocrit test results, ensuring a comprehensive understanding of a patient’s blood health.

Managing Abnormal Hematocrit Levels: Treatment Approaches

When hematocrit levels fall outside the normal range, appropriate management strategies are essential. How are abnormal hematocrit levels treated? Treatment approaches vary depending on the underlying cause and severity of the condition:

Addressing Low Hematocrit

For individuals with low hematocrit levels, treatment may include:

• Iron supplements or dietary changes to address iron deficiency anemia
• Vitamin B12 injections or supplements for pernicious anemia
• Folate supplementation for folate deficiency anemia
• Blood transfusions in severe cases or acute blood loss
• Medications to stimulate red blood cell production, such as erythropoiesis-stimulating agents
• Treatment of underlying chronic conditions contributing to low hematocrit

Managing High Hematocrit

For elevated hematocrit levels, treatment options may include:

• Phlebotomy (blood removal) to reduce blood volume and hematocrit
• Hydration therapy to dilute blood concentration
• Medications to suppress red blood cell production in cases of polycythemia vera
• Lifestyle modifications, such as quitting smoking or relocating to lower altitudes
• Treatment of underlying conditions, such as lung or heart diseases

The specific treatment plan will depend on the individual’s overall health status and the root cause of the abnormal hematocrit levels.

Preventing Hematocrit Abnormalities: Lifestyle and Dietary Considerations

While some factors affecting hematocrit levels are beyond an individual’s control, there are steps one can take to maintain healthy blood composition. How can you promote healthy hematocrit levels? Consider the following preventive measures:

• Maintain proper hydration by consuming adequate fluids throughout the day
• Eat a balanced diet rich in iron, folate, and vitamins B12 and B6
• Exercise regularly to promote overall cardiovascular health
• Avoid tobacco use and limit alcohol consumption
• Manage stress through relaxation techniques or mindfulness practices
• Attend regular check-ups and follow your healthcare provider’s recommendations for blood tests

By adopting these healthy habits, individuals can support optimal hematocrit levels and overall blood health.

The Future of Hematocrit Testing: Advancements and Potential Applications

As medical technology continues to evolve, the field of hematology is experiencing exciting advancements. What innovations are shaping the future of hematocrit testing? Several promising developments are on the horizon:

Point-of-Care Testing

Portable devices for rapid hematocrit testing are becoming increasingly sophisticated, allowing for quick and accurate results in various healthcare settings. These point-of-care tests can provide immediate information, enabling faster clinical decision-making.

Non-Invasive Monitoring

Researchers are exploring non-invasive methods for measuring hematocrit levels, such as optical sensors or wearable devices. These technologies could allow for continuous monitoring without the need for repeated blood draws.

Integration with Artificial Intelligence

The incorporation of artificial intelligence and machine learning algorithms into hematocrit analysis may enhance the accuracy of test interpretation and provide more personalized insights into patient health.

Expanded Applications

Hematocrit testing may find new applications beyond traditional medical settings, such as in sports medicine for monitoring athlete performance and recovery, or in space medicine for assessing astronaut health during long-term missions.

These advancements hold the potential to make hematocrit testing more accessible, efficient, and informative, ultimately improving patient care and outcomes.

As our understanding of blood composition and its impact on overall health continues to grow, the hematocrit test remains a vital tool in medical diagnostics. By providing crucial information about red blood cell levels, this simple yet powerful test plays a key role in identifying and managing a wide range of health conditions. Whether used for routine check-ups or specialized medical investigations, the hematocrit test continues to be an indispensable component of comprehensive healthcare.

Hematocrit Information | Mount Sinai

HCT

Hematocrit is a blood test that measures how much of a person’s blood is made up of red blood cells. This measurement depends on the number of and size of the red blood cells.

Blood transports oxygen and nutrients to body tissues and returns waste and carbon dioxide. Blood distributes nearly everything that is carried from one area in the body to another place within the body. For example, blood transports hormones from endocrine organs to their target organs and tissues. Blood helps maintain body temperature and normal pH levels in body tissues. The protective functions of blood include clot formation and the prevention of infection.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary for this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

The hematocrit is almost always done as part of a complete blood count (CBC).

Your health care provider may recommend this test if you have signs of or are at risk for anemia. These include having:

• Before and after major surgery
• Blood in your stools, or vomit (if you throw up)
• Chronic medical problems, such as kidney disease or certain types of arthritis
• During pregnancy
• Fatigue, poor health, or unexplained weight loss
• Headaches
• Heavy menstrual periods
• Leukemia or other problems in the bone marrow
• Monitoring during treatment for cancer
• Monitoring medicines that may cause anemia or low blood counts
• Monitoring of anemia and its cause
• Poor nutrition
• Problems concentrating

Normal Results

Normal results vary, but in general they are:

• Male: 40. 7% to 50.3%
• Female: 36.1% to 44.3%

For babies, normal results are:

• Newborn: 45% to 61%
• Infant: 32% to 42%

The examples above are common measurements for results of these tests. Normal value ranges vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Low hematocrit may be due to:

• Anemia
• Bleeding

• Bone marrow being unable to produce new red blood cells. This may be due to leukemia, other cancers, drug toxicity, radiation therapy, infection, or bone marrow disorders 

• Chronic illness
• Chronic kidney disease
• Destruction of red blood cells (hemolysis)
• Leukemia
• Malnutrition
• Too little iron, folate, vitamin B12, and vitamin B6 in the diet
• Too much water in the body

High hematocrit may be due to:

• Bone marrow disease that causes abnormal increase in red blood cells (polycythemia vera)
• Congenital heart disease
• Exposure to high altitude
• Failure of the right side of the heart
• Low levels of oxygen in the blood
• Scarring or thickening of the lungs
• Too little water in the body (dehydration)

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood buildup under the skin)
• Infection (a slight risk any time the skin is broken)

Chernecky CC, Berger BJ. H. Hematocrit blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:620-621.

Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM. Blood disorders. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 124.

Means RT. Approach to the anemias. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 149.

Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31.

Last reviewed on: 1/9/2022

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

Hematocrit | Sight Diagnostics

Definition, Test, Low vs High Levels and Causes

What is hematocrit

Hematocrit (HCT) is the calculated volume percentage of red blood cells (erythrocytes) in your blood. Hematocrit is also called packed cell volume (PCV) or erythrocyte volume fraction.

Human blood contains red blood cells, white blood cells, and platelets suspended in a liquid called plasma. The word hematocrit means to separate blood. In a hematocrit test, the red blood cells are separated from the rest of your blood cells and plasma.

Hematocrit is important because red blood cells are essential to your survival. They contain a vital protein component called hemoglobin that binds to oxygen, which fuels all the cells in your body.

When red blood cells pass through your lungs, they bind to and transport oxygen to various cells in your body. On their way back to your lungs, they carry carbon dioxide to be exhaled. Hematocrit is a significant measurement as it can identify whether you have sufficient red blood cells for oxygen transportation and delivery.

If your doctor suspects that you have a blood disorder such as anemia or polycythemia (too many red blood cells), your doctor may order a hematocrit test to check your red blood cells.

How to measure hematocrit with a test?

The original method for hematocrit measurement is the macrohematocrit (Wintrobe hematocrit tube) method.

It uses a narrow glass tube and a centrifuge machine. The centrifuge separates the blood into three main layers: red blood cells, white blood cells, and platelets, in that order from the bottom up. At the very top, there’s a small layer of blood plasma. The macrohematocrit method carries the risk of measuring trapped plasma as part of the red blood cell layer, which erroneously elevates the hematocrit percentage.[1]

A newer method is the microhematocrit method, which uses a capillary tube instead of a narrow glass tube and requires a smaller quantity of blood and less time. The microhematocrit method traps less plasma because the diameter of the capillary tube is smaller than the Wintrobe hematocrit tube. So the percentage of hematocrit is more accurate in the microhematocrit method than in the macrohematocrit method. [1:1]

Both procedures require the technician to manually measure the length of the layers. The technician calculates hematocrit as the length of the packed red blood cell layer divided by the length of total cells and plasma. This ratio is then multiplied by 100 to give a certain percentage.

Today, these two methods have been largely succeeded by an automated hematology analyzer where the hematocrit test is obtained as part of a complete blood count (CBC) laboratory test. The hematocrit is calculated indirectly from the average volume and the number of red blood cells.[2] The automated analyzer is the fastest method. However, automated analyzers may not be available in areas where resources are low.

In the microhematocrit method, a technician only needs a small sample of blood from a finger-prick. In the other methods, the technician draws blood from the inner side of your arm or the back of your hand. Before drawing blood for the measurement, the technician first cleans the surface from where your blood would be drawn. Next, using a needle, the technician draws your blood. Afterward, the technician covers the surface with gauze and a bandage.

What is a normal hematocrit level?

Due to differences in age and gender, the normal hematocrit is a range. Hematocrit results are reported as a percentage. The average hematocrit measurement for human beings is 45%, which means that the red cell volume contains 45 mL per 100 mL of blood.[3]

According to the Cleveland clinic, the general normal ranges for hematocrit are[4]:

• Male: 41% to 50%
• Female: 36% to 44%
• Newborn: 45% to 61%
• Infant: 32% to 42%

What does it mean if your hematocrit is high?

If your hematocrit is high, it means that you have more red blood cells than is considered healthy. 

High hematocrit may be caused by [4:1]:

• Heart disease
• Dehydration
• Scarring or thickening of the lungs
• Bone marrow disease
• Obstructive sleep apnea
• Smoking and chronic obstructive pulmonary disease (COPD)
• Carbon monoxide poisoning
• Testosterone use

A false high hematocrit may be reported if the patient has cryoproteins, significant leukocytosis, or giant platelets. Hematocrit measurement is critically high if it is greater than 67% (>67%).

What does it mean if your hematocrit is low?

If your hematocrit is low, it means that you have fewer red blood cells than is considered healthy.

Low hematocrit may be caused by[4:2]:

• Blood loss
• Leukemia or other bone marrow problems
• Iron and vitamin deficiency, including folate, vitamin B12, and vitamin B6
• Too much water in the body
• Kidney disease
• Thyroid abnormality
• Immune destruction of red blood cells

A false low hematocrit may be reported if the patient has microcytosis, in vitro hemolysis, or autoagglutinins. Hematocrit is considered critically low if it falls below 21% (<21%).

How to increase hematocrit?

In some cases, hematocrit is caused because of low iron levels. You can eat iron-rich foods and take a daily vitamin supplement to help prevent low hematocrit causes.

Food sources that are rich in iron include:

• Red meat
• Beef liver
• Chicken liver
• Fish and shellfish
• Soy products (tofu and edamame)
• Dried fruit
• Green leafy vegetables
• Nuts
• Beans
• Iron-fortified bread and cereals
• Eggs

Additionally, vitamin C helps with iron absorption. Therefore, also eat various foods that are rich in vitamin C, for example, citrus fruits. Do not drink coffee or tea with your meals because this decreases iron absorption.

Discover Sight’s Automated Hematology Analyzer

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“Why is the hematocrit increased in the blood, what does this mean?” — Yandex Q

Yandex.Health

003

Indicator of the level of erythrocytes, leukocytes and platelets for the entire volume of blood in the body is called hematocrit.

Usually this indicator is displayed as a percentage, less often as a fractional number. The definition of this indicator makes it possible to see the presence of any disease and the degree of its development.

The main reason for an increase in hematocrit is an increase in the number of red blood cells (overproduction in the bone marrow) or an increase in their size, which creates additional volume. What does this mean, and what causal factors contribute to this, we will consider in this article.

Hematocrit norm

Blood must be drawn for analysis. The biological material is placed in a sterile flask, after which the vessel is closed and sent to the centrifuge. Here, the blood undergoes a process of separation into its component parts. To do this, it is in a centrifuge for one and a half hours, and during this time all components are separated from each other.

Normal hematocrit values ​​depend on a person’s gender and age:

• adult male – 40-48%;
• adult woman – 36-46%;
• newborn child – up to 60%;
• children under 13 – up to 38-40%.

If the tests show that the norm for women and men is violated and is more than 0.55, then the patient has an increased hematocrit. Due to the high concentration of leukocytes, erythrocytes and platelets in the blood, the viscosity of the blood increases, and this causes the formation and growth of blood clots in the vessels.

signs

The first “bell” in case of hematocrit above normal is frequent dizziness. A high number of red blood cells is able to bind and carry more oxygen, leading to mild but permanent poisoning – hyperoxia.

As the disease progresses, the poisoning becomes more severe, causing nausea, a state of slight dazedness, numbness of the extremities, and difficulty in breathing.

Causes of increased hematocrit

Why is the hematocrit in the blood of adults elevated, what does this mean? The reasons for the increase in hematocrit can be both pathological and physiological, which are not associated with certain diseases.

The body always strives to maintain the balance of internal processes, therefore, in case of deviations from physiological norms, compensatory mechanisms are activated. An increase in hematocrit in the blood is one of the quantitative characteristics of the physiological “adjustment” of the body to new living conditions.

So, let’s look at the most common causes of increased hematocrit in adults:

1. As a result of dehydration, or dehydration. In this case, the amount of circulating blood in the bed decreases due to a decrease in plasma volume. This can happen with vomiting, diarrhea, overheating, heavy sweating, and insufficient fluid intake. In this case, the body is forced to take water from the bloodstream. Thus, the ratio of the volume of the erythrocyte fraction and the total volume changes, the blood becomes thicker due to a decrease in the amount of plasma.
2. Diseases that reduce the volume of plasma in the blood. They do not affect the amount of blood elements themselves, but second-degree burns, for example, form blisters in which plasma accumulates. It is taken just from the blood, increasing the hematocrit by reducing the second number in the indicator. Also, this group includes acute manifestations of diseases such as peritonitis, thrombosis or diabetes.
3. Chronic hypoxia. In this state, there is not enough oxygen in the cells and tissues of the human body. Pathology is often detected in people who smoke or

   suffer from diabetes

   . Erythrocytes contain hemoglobin, which is responsible for the movement of oxygen, its transportation to cells, and the removal of carbon dioxide from the body. With hypoxia, which is present in a chronic form and has arisen for an objective reason, the body tries to eliminate the problem of oxygen deficiency by increased synthesis of red blood cells. The increase in hematocrit in this case occurs precisely because of the increased production of red blood cells.

4. Long-term use of drugs: glucocorticoids and other hormonal drugs are especially dangerous in this regard. Diuretics also have a similar effect.
5. Obtaining skin burns. Moreover, the larger the area of ​​the skin lesion, the higher the hematocrit is recorded in the blood test. This is easily explained by the mobilization of all blood components to fight infections and bacteria penetrating the burn, as well as the need for an accelerated process of tissue regeneration.
6. Diseases of the kidneys. Hydronephrosis, which reduces the body’s ability to absorb water, or neoplasms, polycystic, accompanied by an increased release of erythropoietin, the hormone responsible for the formation of red blood cells.

7. Anemia

   , in which the body has a lack of vitamin B12 and iron.

8. Blood disease, primarily leukemia.
9. Development of peritonitis in the body.
10. Polycystic disease in acute or chronic forms.
11. Rapid development of erythremia in the body.

It is obvious that an analysis of only hematocrit without determining the number of erythrocytes and their morphological features is unlikely to satisfy the demands of clinicians in the diagnosis of various hematological pathologies, since the test, although it carries general information, does not reveal the reason for the increase or decrease.

Therefore, when this value exceeds the norm, this can indicate both physiological processes in the body and diseases. A high hematocrit indicates thick blood, which means that there is a risk of developing thrombosis.

What can affect the hematocrit rate?

An increase, as well as a decrease in hematocrit, is not necessarily associated only with diseases or external influences in the form of injury or burns. There are at least two more factors that affect the increase in hematocrit.

1. In those who smoke, the hematocrit increases due to oxygen starvation of tissues, they produce red blood cells at an increased level.
2. People who are forced to work or constantly be at height are also characterized by an increase in the level of hematocrit in the blood. This applies to climbers or just residents of high mountain areas. This factor is very similar to the previous one, because a person receives an insufficient amount of oxygen – its concentration decreases as the altitude increases.
3. An elevated Ht level is typical for athletes using anabolic steroids to gain muscle mass.
4. In newborns, the hematocrit is always elevated.

So, it is very important to take a hematocrit test in order to detect the development of certain pathologies in time.

What to do with elevated hematocrit?

Successful treatment and stabilization of the hematocrit level is based on the elimination of the underlying cause. In some cases, no special methods can be applied, it is enough to start breathing oxygen-enriched air, stop smoking, drink enough water and normalize your lifestyle. Also, with a strong increase in hematocrit, it is necessary to consult a doctor for the appointment of drugs that thin the blood – anticoagulants.

It is worth remembering that in the case of an increase in hematocrit, blood viscosity also increases. This leads to certain consequences. The risk of blood clots, which subsequently block arterial blood flow, increases. This may lead to

heart attacks

, ischemic stroke, gangrene or death depending on the location of the thrombus.

We’ve put together the most helpful information on what it means to have an “elevated hematocrit” so that you can now have an initial idea of ​​your CBC results. Leave comments and share useful information with your loved ones.

Consequences

An increase in hematocrit is directly related to an increase in blood viscosity.

Thick blood is prone to the formation of clots, which, having gathered in a certain amount, already form a thrombus. Small blood clots begin to block the blood flow in thin capillary vessels, thereby blocking the nutrition of small areas of tissues first. A person can feel such overlap in the form of numbness, for example, fingers, toes, as well as the death of small areas of tissue.

But large blood clots can cause, first of all, big problems with the heart, up to death.
The way out of the current situation in blood thinning. This is a well-known recommendation.

Material provided

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Automatic blood test – normal values ​​of erythrocyte levels – Article in Yekaterinburg

Traditional manual and modern automated methods used in hematological studies differ in results. This is due to their metrological differences. The following are the values ​​that can be obtained from laboratory tests in various groups of patients.

Hemograms obtained from the use of hematology analyzers in adult patients. Erythrocytes Men (RBC) 3.8 – 5.1 t/l* 4.3 – 5.7 t/l l* Hemoglobin (HGB) 117 – 160 g/l 131 – 173 g/l Hematocrit (HCT) 35 – 45% 39 – 50% MCV 80 – 100 fl* 80 – 100 fl* MCH 901 27

27 – 34 pg* 27 – 34 pg* MCHC 32 – 36 g/dl 32 – 37 g/dl RDW 11. 6 – 14.8% 11.6 – 14.8% 9012 7 Platelets (PLT) 150 – 400 G/l* 150 – 400 G/l* Leukocytes (WBC)** 3.5 – 11.0 G/L* 4.9 – 10.5 G/L* Leukocytes (WBC)*** 4.0 – 9.0 G/L* 4.0 – 9.0 G/L*

*Hereinafter

• G/L – Giga/L = 10 ⁹ /L
• T/L – Tera/l = 10 ¹² /l
• fl – femtoliter
• pg – pictograms

from English. / ed. WELL. Titsa. – M.: Medicine, 1986, 480 p.

***The values ​​were developed by the working group of experts at VNMCC on laboratory business and approved by the Ministry of Health of the USSR in 1978 Women (g/l) Men (g /l) Cord blood 135 – 205 135 – 205 134 – 198 134 – 198 1 month 107 – 171 107 – 171 2 months 94 – 130 94 – 130 4 months 103 – 141 103 – 141 6 months 111 – 141 111 – 141 9 months 114 – 140 114 – 140 1 – 2 years 113 – 141 113 – 141

9 0136

2 – 5 years 110 – 140 110 – 140 5 – 9 years 115 – 145 115 – 145 years 120 – 150 120 – 150 12 – 14 years 115 – 150 120 – 160 15 – 17 years 117 – 153 117 – 166 18 – 44 117 – 155 132 – 173 45 – 64 years old 117 – 160 131 – 172 65 – 74 117 – 161 126 – 174

900 08 For research, venous or capillary blood with EDTA salts is taken. When performing studies on hematological analyzers, the photometric method is used.

Errors in hemoglobin measurement

Inflated concentration results may be due to the following factors:

• Hyperlipidemia.
• Hyperbilirubinemia.
• Cryoglobulinemia.
• High leukocytosis.
• Excess of unstable hemoglobins.

Clinical and diagnostic value:

• Increased concentration is caused by dehydration, as well as primary or secondary erythremia.
• Decreased concentration occurs with anemia or overhydration.

Some patients who have a hemoglobin level higher than 75 g/l can increase their hemoglobin levels by 20-30 g/l by taking iron supplements for 10 days, but the iron deficiency itself is not compensated. If the patient (body weight 70 kg) also receives a blood transfusion (500 ml), an increase in hemoglobin level by 12 g/l is possible.

Erythrocytes

Normal values ​​

9 0136

Age	Women (t/l)	Men (t/l)
Cord blood	3. 9 – 5, 5	3.9 – 5.5
2 wk.	3.9 – 5.9	3.9 – 5.9
1 month	3.3 – 5.3	3.3 – 5.3
4 months	3.5 – 5.1	3.5 – 5.1
6 months	3.9 – 5.5	3.9 – 5.5
9 months	4.0 – 5.3	4.0 – 5.3
1 – 2 years	3.8 – 4.8	3.8 – 4.8
3 – 8 years	3.7 – 4.9	3.7 – 4.9
9 – 12 years	3.9 – 5.1	3.9 – 5.1 901 27
12 – 14 years old	3.8 – 5.0	4.1 – 5.2
15 – 17 years old	3.9 – 5.1	4.2 – 5.6
18 – 44 years old 9 0127	3.8 – 5, 1	4.3 – 5.7
45 – 64 years	3.8 – 5.3	4.2 – 5.6
65 – 74 years old	3. 8 – 5.2	3.8 – 5.8

Venous or capillary blood with EDTA salts is used for research.

Clinical and diagnostic value

The number of red blood cells increases with:

• Dehydration.
• Reactive erythrocytoses, which are caused by a lack of oxygen in the tissues due to congenital or acquired heart defects, with cor pulmonale, frequent stay at high altitudes, with emphysema.
• Reactive erythrocytosis caused by Cushing’s disease or syndrome, taking corticosteroids, dropsy of the renal pelvis, various neoplasms, erythremia, polycystic kidney disease.

The number of erythrocytes decreases with:

• Anemia;
• Hyperhydration.
• Major blood loss.
• Late pregnancy.

Hematocrit

9013 6

90 136

Age	Women	Men
Umbilical cord blood	42 – 60%	42 – 60%
2 wk.	41 – 65%	41 – 65%
1 month	33 – 55%	33 – 55%
2 months	28 – 42%	28 – 42%
4 months	32 – 44%	32 – 44%
6 months	31 – 41%	31 – 41%
9 months	32 – 40%	32 – 40%
1 year	33 – 41%	33 – 41%
1 – 2 years	32 – 40%	32 – 40%
3 – 5 years	32 – 42%	32 – 42%
6 – 8 years	33 – 41%	33 – 41%
9 – 11 years	34 – 43%	34 – 43%
12 – 14 years	34 – 44%	35 – 45%
15 – 17 years	34 – 44%	37 – 48%
18 – 44	35 – 45%	39 – 49%
45 – 64	35 – 47%	39 – 50%
65 – 74 years old	35 – 47%	37 – 51%

Venous blood with EDTA salts and capillary blood collected in a hematocrit capillary are used for research. In modern analyzers, hematocrit (Hct) is a secondary calculated parameter.

False hematocrit possible at:

• Development of cryoglobulinemia.
• The presence of huge platelets in the sample.
• Increased white blood cell count (more than 50 g/l).
• Hyperglycemia (more than 33.3 mmol/l).

False low in hardware analysis causes:

• RBC agglutination.
• Microerythrocytosis (less than 36 vials).

Clinical and diagnostic value:

An increase in hematocrit is observed when being at high altitude, the presence of neoplasms in the kidneys or their polycystic, chronic lung diseases, erythrocytosis, or conditions leading to a decrease in the volume of plasma circulating in the body – diabetes, non-stop vomiting, increased sweating).

The hematocrit value decreases with anemia or due to an increase in the volume of circulating plasma during pregnancy, overhydration.

Mean erythrocyte hemoglobin (MHC)

9 0124 45 – 64

Age	Women (pg)	Men (pg)
Cord blood	31 – 37	31 – 37
2 weeks	30 – 37	30 – 37
1 month	29 – 36	29 – 36
2 months	27 – 34	27 – 34
4 months	25 – 32	25 – 32
6 months	24 – 30	24 – 30
9 months	25 – 30	25 – 30
1 year	24 – 30	24 – 30
1 – 2 years	22 – 30	22 – 30
3 – 8 years	25 – 31	25 – 31
9 – 14 years 9012 7	26 – 32	26 – 32
15 – 17 years old	26 – 34	27 – 32
18 – 44	27 – 34	27 – 34
27 – 34	27 – 35
65 – 74 years	27 – 35	27 – 34

Venous or capillary blood with EDTA salts is used for research.

MHC is used to determine the average hemoglobin content in a single erythrocyte. To calculate the parameter, the following formula is used:

MHC pg \u003d Hb g / l / RBC T / l

The numerator is the total indicator of hemoglobin.

The denominator is the total number of erythrocytes.

The parameter is defined in picograms. To determine the average amount of hemoglobin in erythrocytes, a parameter such as a color index – CPU is also used. It is defined in conventional units.

CP = Hb g % * 3 / first 2 digits of RBC count

Or calculated as follows:

CP = MCH pg / 33.4

CP can completely replace MCH. If an automatic hematology analyzer is used for studies that calculates the MCH value, then there is no need to additionally determine the CPU.

Hyperchromia or an increase in MCH greater than 34 pg is not due to an increase in the concentration of hemoglobin in erythrocytes, but is caused by an increase in their volume. A false overestimation of this indicator is possible with errors due to an increased level of hemoglobin and a reduced number of red blood cells. A decrease in MCH to a value of 27 pg or less is called hypochromia.

Clinical and diagnostic value:

• An increase is possible with anemia due to cirrhosis of the liver, hyperchromic or megaloblastic anemia.
• Decrease causes anemia in malignant neoplasms, hypochromic anemia.

Mean erythrocyte hemoglobin concentration MCHC

Age	Women/Men (g/dl)
Cord blood	30 – 36
2 weeks	28 – 35
1 month	28 – 36
2 months	28 – 35
4 months	29 -37
6 – 12 months	32 – 37
1 – 2 years	32 – 38
3 – 74 years	32 – 37 901 27

The study is carried out using venous or capillary blood with EDTA salts. The indicator characterizes the amount of hemoglobin in the average erythrocyte and is calculated in% according to the following formula:

MCHC = Hb g/l * 10 / Ht %

This is one of the most stable and genetically determined parameters that is not affected by age, gender or race. The concentration of hemoglobin depends on the structure of the cell and does not change throughout life, so the limits of the norm are quite narrow and practically not subject to fluctuations in various pathologies.

There is a clearly defined upper limit for the MCHC. This parameter may be incorrectly determined by inaccurate counting of the number of red blood cells. With it, it is convenient to control the accuracy of the device.

Clinical and diagnostic value:

• An increased value occurs with hypertensive disorders in the water-electrolyte system or hyperchromic anemia.
• A decrease in the values ​​of the indicator is typical for hypotonic disorders of the water and electrolyte balance or hypochromic anemia.

Important! Since the maximum value of hemoglobin solubility in water is 37 g / dl, an excess of an MCHC value of more than 37 indicates the need for a second study. An increased value can also cause hemolysis.

Accurately determine the violations in the water-electrolyte balance should be using not the absolute values ​​of MCHC, but their dynamics.

MCV

Age	Women (fl)	Men (fl) 9 0127
Cord blood	98 – 118	98 – 118
2 weeks	80 – 140	80 – 140
1 month	91 – 112	91 – 112
2 months	84 – 106	84 – 106
4 months	76 – 97	76 – 97
6 months	68 – 85	68 – 85
9 months	70 – 85	70 – 85
1 year	71 – 84	71 – 84
2 – 5 years	73 – 85	73 – 85
5 – 9 years	75 – 87	75 – 87
9 – 12 years	76 – 90 9012 7	76 – 90
12 – 14 years	73 – 95	77 – 94
15 – 17 years old	80 – 96	79 – 95
18 – 44 years old	81 – 100	80 – 99
45 – 64	81 – 101	81 – 101
65 – 74 years	81 – 102	81 – 103

Almost all modern hematology analyzers can measure this indicator. Data are given in units of femtoliters – fm.

You can also use the formula to calculate:

MCV fl = Hct % * 10 / RBC T/L

The average red blood cell volume changes throughout life. It allows you to quantify microcytosis or macrocytosis. The value of this indicator can be effectively used in the differential diagnosis of anemia.

It is the average volume rather than the diameter of erythrocytes that is more objective in clinical studies. This is due to the fact that the diameter can vary significantly under the influence of normal physiological factors – time of day, physical activity. In automatic analysis, blood is diluted in an isotonic solution, which has constant physico-chemical parameters, ensuring stability when measuring MCV.

MCV rate is 80 to 100 fl. Volume distribution curves are shown in the graph.

The body itself regulates the number of red blood cells and the level of hemoglobin, ensuring their relative constant ratio. The relationship between the number of red blood cells and their average volume is shown in the graph:

Clinical and diagnostic value:

• Less than 80 fl. Microcytic anemia, or accompanied by microcytosis.
• 80 to 100 vials Normocytic anemia, or accompanied by normocytosis.
• Over 10 vials Macrocytic and megablast anemia, as well as those accompanied by macrocytosis.

RBC anisocytosis RDW

Values ​​between 11.6-14.8% are considered normal.

This parameter characterizes the width of the distribution of erythrocytes. The function of determining this value is incorporated in most modern models of hematological analyzers. Calculated using the formula:

RDW % = SD / MCV fl * 100%

SD is the standard deviation of red blood cell volume from the mean value.

In a healthy person, the normal value may be 12-14%. There are no conditions that can cause this parameter to decrease. Due to differences in blood processing algorithms, even in different devices, different values ​​​​of this indicator can be obtained.