What does a low hematocrit (HCT) level indicate in a blood test. How is HCT measured and what are the normal ranges. What are the potential causes of low HCT and when should you be concerned. What treatment options are available for low HCT.

Understanding Hematocrit (HCT) in Blood Tests

Hematocrit (HCT) is a crucial component of a complete blood count (CBC), providing valuable insights into a person’s overall health. HCT measures the percentage of blood volume occupied by red blood cells. This measurement is essential for diagnosing various conditions, including anemia and dehydration.

How is HCT measured? Typically, a blood sample is taken and spun in a centrifuge to separate the blood components. The packed red blood cells are then compared to the total blood volume to determine the HCT percentage.

Normal HCT Ranges

• Adult males: 40.7% to 50.3%
• Adult females: 36.1% to 44.3%
• Children: Ranges vary by age and gender
• Newborns: 45% to 61%

It’s important to note that these ranges can vary slightly depending on the laboratory and testing method used. Always consult with your healthcare provider for interpretation of your specific results.

Implications of Low HCT in Blood Tests

A low HCT result can be indicative of several health issues. The primary concern with low HCT is anemia, a condition characterized by a decrease in the number of red blood cells or their oxygen-carrying capacity.

What are the symptoms of low HCT? Common signs include:

• Fatigue and weakness
• Shortness of breath
• Dizziness
• Pale skin
• Cold hands and feet
• Chest pain or irregular heartbeat

These symptoms occur because low HCT often means there are fewer red blood cells to carry oxygen throughout the body, leading to various physiological responses.

Common Causes of Low HCT

Understanding the potential causes of low HCT is crucial for proper diagnosis and treatment. Some common reasons include:

1. Blood loss: Acute or chronic bleeding from injury, surgery, or gastrointestinal issues
2. Nutritional deficiencies: Particularly iron, vitamin B12, or folate deficiencies
3. Bone marrow disorders: Conditions affecting red blood cell production
4. Chronic diseases: Such as kidney disease, cancer, or autoimmune disorders
5. Hemolysis: Premature destruction of red blood cells
6. Pregnancy: Due to increased blood volume and iron requirements
7. Overhydration: Excessive fluid intake diluting blood concentration

Identifying the underlying cause is essential for developing an effective treatment plan. Your healthcare provider may order additional tests to determine the specific reason for your low HCT.

Diagnostic Procedures for Low HCT

When a low HCT is detected, healthcare providers typically conduct further investigations to determine the root cause. These may include:

• Complete blood count (CBC): To assess other blood components and indices
• Peripheral blood smear: Examination of blood cells under a microscope
• Iron studies: To check for iron deficiency anemia
• Vitamin B12 and folate tests: To identify potential nutritional deficiencies
• Reticulocyte count: To assess bone marrow response
• Hemoglobin electrophoresis: To detect abnormal hemoglobin variants
• Bone marrow biopsy: In cases of suspected bone marrow disorders

The choice of diagnostic procedures depends on the patient’s medical history, symptoms, and initial test results. A comprehensive approach ensures accurate diagnosis and appropriate treatment.

Treatment Options for Low HCT

The treatment for low HCT varies depending on the underlying cause and severity of the condition. Some common approaches include:

1. Iron supplementation: For iron deficiency anemia
2. Vitamin B12 injections: In cases of B12 deficiency
3. Folic acid supplements: To address folate deficiency
4. Erythropoiesis-stimulating agents: To boost red blood cell production
5. Blood transfusions: For severe anemia or acute blood loss
6. Treatment of underlying conditions: Such as kidney disease or cancer
7. Dietary changes: To increase intake of iron-rich foods
8. Medications: To address specific causes like hemolysis or bone marrow disorders

The effectiveness of treatment is monitored through regular blood tests, including HCT measurements. Your healthcare provider will adjust the treatment plan as needed based on your response and progress.

Preventing Low HCT: Lifestyle and Dietary Considerations

While not all causes of low HCT are preventable, certain lifestyle and dietary choices can help maintain healthy HCT levels:

• Consume a balanced diet rich in iron, vitamin B12, and folate
• Include lean meats, leafy greens, legumes, and fortified cereals in your diet
• Stay hydrated, but avoid overhydration
• Exercise regularly to stimulate red blood cell production
• Manage chronic conditions effectively
• Avoid excessive alcohol consumption
• Don’t smoke or use tobacco products
• Consider iron supplements if you’re at risk of deficiency (consult your doctor first)

By adopting these habits, you can support your body’s ability to maintain healthy red blood cell levels and potentially prevent low HCT.

Low HCT in Special Populations

Certain groups may be more susceptible to low HCT or require special consideration in diagnosis and treatment:

Pregnant Women

Pregnancy naturally leads to a decrease in HCT due to increased blood volume. However, severe anemia during pregnancy can pose risks to both mother and fetus. Regular prenatal check-ups and iron supplementation are often recommended.

Athletes

Endurance athletes may experience a condition called “sports anemia,” characterized by slightly lower HCT levels. This is often due to plasma volume expansion and is generally not a cause for concern. However, true anemia in athletes should be addressed to maintain performance and health.

Elderly Individuals

Older adults are more susceptible to anemia due to various factors, including chronic diseases, nutritional deficiencies, and medications. Regular health check-ups and appropriate interventions are crucial for this population.

Individuals with Chronic Diseases

Those with conditions like kidney disease, cancer, or autoimmune disorders may experience persistently low HCT. Management of the underlying condition, along with specific treatments for anemia, is often necessary.

The Role of HCT in Overall Health Assessment

While HCT is a valuable indicator of health, it’s important to consider it in conjunction with other blood parameters and clinical findings. Healthcare providers use HCT as part of a comprehensive health assessment, considering factors such as:

• Other CBC components (hemoglobin, red blood cell count, etc.)
• Patient’s medical history and current symptoms
• Presence of chronic conditions
• Medications and supplements being taken
• Lifestyle factors (diet, exercise, stress levels)
• Recent medical procedures or injuries

This holistic approach ensures that HCT results are interpreted accurately within the context of an individual’s overall health status.

Technological Advancements in HCT Testing

Recent developments in medical technology have improved the accuracy and accessibility of HCT testing:

1. Point-of-care testing: Allows for rapid HCT measurement in various clinical settings
2. Automated hematology analyzers: Provide quick and precise results for large-scale testing
3. Non-invasive HCT monitoring: Emerging technologies for continuous monitoring without blood draws
4. Artificial intelligence in result interpretation: Enhances accuracy and identifies subtle patterns
5. Integration with electronic health records: Improves tracking and analysis of HCT trends over time

These advancements contribute to more efficient diagnosis and management of conditions associated with low HCT.

When to Seek Medical Attention for Low HCT

While mild fluctuations in HCT are often benign, certain situations warrant prompt medical attention:

• Severe or persistent symptoms of anemia
• Rapid drop in HCT levels
• HCT below 30% in adults
• Signs of internal bleeding
• Unexplained fatigue or weakness
• Chest pain or shortness of breath
• Dizziness or fainting spells

If you experience any of these symptoms or have concerns about your HCT levels, consult your healthcare provider promptly. Early intervention can prevent complications and improve outcomes.

Understanding the significance of HCT in blood tests empowers individuals to take an active role in their health management. By recognizing the implications of low HCT, identifying potential causes, and seeking appropriate medical care, you can address this condition effectively and maintain optimal health.

Remember, while HCT is an important health indicator, it’s just one piece of the puzzle. Always consult with healthcare professionals for personalized advice and comprehensive health assessments. Regular check-ups and open communication with your medical team are key to maintaining healthy HCT levels and overall well-being.

Blood Tests Explained | Alta Rancho Pet & Bird Hospital

Blood tests help doctors determine causes of Illness accurately, safely, and quickly and let us monitor the progress of medical treatments. To help you understand your pet’s test results, this guide explains common tests. We want you to understand our recommendations and be a partner in your pet’s care.

Complete blood count (CBC)

This is the most common blood test performed on pets and people. A CBC gives information on hydration status, anemia, infection, the blood’s clotting ability, and the ability of the immune system to respond. This test is essential for pets with fevers, vomiting, diarrhea, weakness, pale gums, or loss of appetite. If your pet needs surgery, a CBC can help detect bleeding disorders or other unseen abnormalities.

HCT (hematocrit) measures the percentage of blood made up by red blood cells. Low numbers indicate anemia (blood loss) while high numbers may indicate dehydration or other problems.

Hb and MCHC (hemoglobin and mean corpuscular hemoglobin concentration) Hemoglobin is the molecule that carries oxygen in the blood. Low numbers indicate problems with the ability to carry oxygen.

WBC (white blood cell count) measures the body’s immune cells. High numbers may indicate infection, inflammation or cancer. Low numbers may indicate immune suppression, cancer or overwhelming infection.

GRANS and L/M (granulocytes and lymphocytes/monocytes) are specific types of white blood cells.

EOS (eosinophils) are a specific type of white blood cells that may indicate allergic or parasitic conditions.

PLT (platelet count) measures cells that form blood clots.

RETICS (reticulocytes) are immature red blood cells. High levels indicate regenerative anemia.

Blood Chemistries

These common blood serum tests evaluate organ function, electrolyte status, hormone levels, and more. They are important in evaluating any sick pet, pets receiving long-term medications, pet’s undergoing anesthesia and as screening tests for elderly pets.

ALB (albumin) Is a serum protein that helps evaluate hydration, hemorrhage, and intestinal, liver, and kidney disease.

ALKP (alkaline phosphatase) elevations may indicate liver damage, Cushing’s disease, uterine infection, bone cancer and active bone growth in young pets. This test is especially significant in cats.

ALT (alanine aminotransferase) is a sensitive indicator of active liver damage but doesn’t indicate the cause.

AMYL (amylase) elevations help us evaluate pancreatitis.

AST (aspartate aminotransferase) increases may indicate liver, heart, or skeletal muscle damage.

BUN (blood urea nitrogen) indicates kidney function. An increased blood level is called azotemia and can be caused by kidney, liver, and heart disease, urethral obstruction, shock, and dehydration.

Ca (calcium) deviations can indicate a variety of diseases. Cancer, hyperparathyroidism, kidney disease, vitamin D toxicity and low albumin are just a few of the conditions that alter serum calcium.

CHOL (cholesterol) is used to supplement diagnosis of hypothyroidism, liver disease, Cushing’s disease, and diabetes mellitus.

CI (chloride) is an electrolyte often lost with vomiting and Addison’s disease. Elevations often indicate dehydration.

Cortisol is a hormone that is involved in stress response. High numbers may indicate Cushing’s disease while low numbers may indicate Addison’s disease (ACTH stimulation test).

CREA (creatinine) reveals kidney function. High numbers indicate loss of kidney function but not the cause

GGT (gamma glutamyl transferase) is an enzyme that indicates liver disease or corticosteroid excess.

GLOB (globulin) is a blood protein that often increases with chronic inflammation and certain disease states.

GLU (glucose) Is a blood sugar. Elevated levels may indicate diabetes mellitus. Low levels can cause collapse, seizures, or coma.

K (potassium) is an electrolyte lost with vomiting, diarrhea, or excessive urination. Increased levels may indicate kidney failure, Addison’s disease, dehydration, and urethral obstruction. High levels can lead to cardiac arrest. Low levels lead to weakness and disorientation.

LIP (lipase) is an enzyme that may indicate pancreatitis when it is elevated.

Na (sodium) is an electrolyte lost with vomiting, diarrhea, and kidney and Addison’s disease. This test helps indicate hydration status.

PHOS (phosphorus) elevations are often associated with kidney disease, hyperthyroidism, and bleeding disorders.

TBIL (total bilirubin) elevations may indicate liver or hemolytic disease. This test helps identify bile duct problems and certain types of anemia.

TP (total protein) indicates hydration status and provides additional information about the liver, kidneys, and infectious diseases.

T4 (thyroxine) is a thyroid hormone. Decreased levels often signal hypothyroidism in dogs, while high levels Indicate hyperthyroidism in cats.

While fully understanding and interpreting laboratory tests takes years of training, we hope that this handout has helped you understand some basic concepts behind the tests we regularly run on your pets. If you have any questions about your pet’s laboratory results, or any aspect of his/her health care, feel free to speak with any of our well trained staff members or with our veterinarians.

PCV – Understand the Test

Also Known As

Packed cell volume

haematocrit

Formal Name

At a Glance

Why Get Tested?

If your doctor suspects that you have anaemia (too few red blood cells), polycythaemia (too many red blood cells), or dehydration

When To Get Tested?

As part of a full blood count (FBC), a general blood screening test which may be requested for a variety of symptoms such as headaches, blurred vision, tiredness, itchy skin, difficulty in breathing and dizziness.

Sample Required?

A blood sample taken from a vein in your arm or by a finger-prick (children and adults) or heel-prick (newborns)

Test Preparation Needed?

No test preparation is needed

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc. ), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual’s health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

Blood is a mixture of cells and plasma. The packed cell volume (PCV) is a measurement of the proportion of blood that is made up of cells. The value is expressed as a percentage or fraction of cells in blood. For example, a PCV of 40% means that there are 40 millilitres of cells in 100 millilitres of blood.

Red blood cells account for nearly all the cells in the blood. The PCV increases when the number of red blood cells increases or when the total blood volume is reduced, as in dehydration. The PCV falls to less than normal, indicating anaemia, when your body decreases its production of red blood cells or increases its destruction of red blood cells, or the blood cells are diluted by increases in total volume (haemodilution, for example occurring during pregnancy).

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Common Questions

• How is it used?

  This test is used to diagnose or evaluate anaemia (decrease of red blood cells), polycythaemia (increase in red blood cells) or dehydration; which may be referred to as relative polycythaemia.

• When is it requested?

  The PCV is normally requested as a part of the full blood count (FBC). It is also repeated at regular intervals for many conditions, including:  

  • Monitoring treatment of anaemia, polycythaemia or dehydration.
  • Monitoring the need for or effectiveness of blood transfusions, monitoring of ongoing bleeding to check its severity.

• What does the test result mean?

  A decreased PCV indicates anaemia, or haemodilution. Haemodilution is usually obvious due to administration of a bolus of intravenous fluids (water containing solutions into the blood stream) or pregnancy. Further testing may be necessary to determine the exact cause of anaemia.

  Conditions that can result in a low PCV include

  • Bleeding
  • Nutritional – iron, vitamin (e.g. B12 or folate) or other mineral deficiencies
  • Inflammatory conditions such as rheumatoid arthritis
  • Kidney disease (healthy kidneys secrete a hormone erythropoietin or “epo” which stimulates red blood cell production in the bone marrow)
  • Cirrhosis of the liver
  • Haemolysis, where the red cells are being destroyed prematurely either due to attack by the body’s immune system, due to organ damage or due to inherited abnormalities of the red cells or the haemoglobin they contain
  • Bone marrow disorders such as aplastic anaemia, myelodysplastic syndrome, leukaemia, lymphoma or myeloma
  • Some medicines– including chemotherapy

  The most common cause of increased PCV is dehydration, and with adequate fluid intake, the PCV returns to normal. However, it may reflect a condition called polycythaemia where there are too many red cells.

  In primary polycythaemia (polycythaemia vera, PV, or, polycythaemia rubra vera, PRV) the bone marrow overproduces red blood cells of its own accord.

  More commonly polycythaemia is due to factors outside the bone marrow (secondary polycythaemia). Causes of secondary polycythaemia include:

  • Some lung or heart diseases where the bone marrow manufacturers more red blood cells in order to carry enough oxygen throughout your body
  • Excessive alcohol consumption
  • Smoking
  • Liver or kidney disease
  • Obesity
  • Drug induced – testosterone, growth hormone, EPO and diuretics
  • Some tumours which can secrete erythropoietin (“epo”), stimulating the production of red blood cells
  • Rare inherited haemoglobins, which don’t release enough oxygen to the body

• Is there anything else I should know?

  Pregnancy usually causes a slightly decreased PCV due to extra fluid in the blood.

  Living at high altitudes causes an increased PCV – this is your body’s response to the decreased pressure of oxygen available at these heights.

  Recent blood transfusion may give a misleading result.

  You may have an ultrasound scan of the kidneys if a high PCV result is detected and possibly a blood test called EPO and JAK2.

  In polycythaemia vera you may also have increased white cell cells and platelets.

• How do you treat anaemia?

  Treatment will depend upon the type of anaemia and the cause. Folic acid, vitamin B12 replacement, iron, and packed red cell transfusion are some therapies used to treat anaemia.

• How do you treat polycythaemia?

  Treatment aims to prevent symptoms and complications and treat underlying causes. This may be done by removing blood or taking medication to reduce PCV. You may be given medication to prevent blood clots. Improving lifestyle such as stopping smoking, drinking less alcohol and losing weight can decrease risk of potential blood clots.

• Can I measure my PCV at home?

  No. This test is performed by trained laboratory personnel.

• Is anyone more at risk for abnormal PCV values?

  People who have a chronic illness (such as rheumatoid arthritis), an inherited blood disorder, or malnutrition are at risk for an abnormal PCV. Women of childbearing age may have temporary decreases in PCV during menstrual periods and pregnancy.

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Why is a general blood test prescribed and what does it show?

Complete blood count is a traditional tool for medical diagnostics. This research method allows you to assess the general state of human health, and is also used to diagnose and control the treatment of many diseases. In this article, you will learn what exactly this analysis shows and how to decipher its indicators.

This test is for:

• General health assessments.
• Diagnostics of various diseases and disorders such as anemia, inflammation, infection, bleeding disorders, leukemia.
• Monitoring the effectiveness of treatment after the initial diagnosis.
• Monitor treatments that may affect blood cells – these treatments include radiation and chemotherapy.

This test counts the number of blood cells that circulate in the blood. The latter consists of three types of cells suspended in plasma: white blood cells (leukocytes), red cells (erythrocytes), and platelets. They are primarily produced and matured in the bone marrow and released into the bloodstream as needed.

Complete blood counts provide information about more than just cell count. They may also indicate the physical characteristics of some of them. Standard analysis evaluates:

1. White cells (leukocytes): calculation of their total number; also this indicator may include the differentiation of leukocytes.
2. Red blood cells (erythrocytes): calculation of their total number. This also includes hemoglobin, hematocrit, and erythrocyte indices. These indices include: the average corpuscular volume of erythrocytes, the average erythrocyte hemoglobin, the average concentration of corpuscular hemoglobin and the width of the distribution of erythrocytes. The red blood cell score may also include the reticulocyte count.
3. Platelets : their total number; may include mean platelet volume and/or platelet distribution width.

If the parameters of the general blood test have significant deviations in one or more components, this may indicate the presence of a pathological process in the body. In this case, the patient is prescribed additional tests that are necessary to clarify the cause of the abnormal performance. As a rule, in this situation, a blood smear is examined under a microscope: the appearance and physical properties of blood cells are evaluated. These properties include the size, shape, and color of blood cells. This provides the doctor with additional information and helps determine the cause of abnormal readings.

Detailed interpretation of the complete blood count

In order for you to better understand what certain indicators indicate, we will take a closer look at the properties and components of blood cells.

White blood cells

There are 5 types of white blood cells, also called leukocytes. They help maintain health by fighting infections. These include: neutrophils, lymphocytes, basophils, eosinophils and monocytes. These cells are in the blood in a relatively stable concentration, however, depending on what is happening in the body, the rate of white blood cells in the blood may change for a while.

For example, a bacterial infection can stimulate our bodies to produce more neutrophils. If a person has an allergy, he may experience an increase in the concentration of eosinophils in the blood. When lymphocytes in the blood rise above normal, this indicates a possible viral infection in the body. In some disease states, such as leukemia, white cells multiply rapidly, causing the total number of white cells in the blood to rise.

Red blood cells

Red blood cells are produced in the bone marrow and released into the bloodstream as they mature. They contain hemoglobin, a protein that transports oxygen to all body tissues. The typical lifespan of red cells is 120 days. For this reason, the bone marrow must constantly produce new red blood cells in place of the old ones that decay. Many disorders can affect the production of red blood cells, as well as their lifespan. Plus, some diseases can lead to significant blood loss. That is why the indicators of red blood cells in the blood are extremely important for human health.

Complete blood count does not only count the total number of red blood cells. This study makes it possible to estimate the amount of hemoglobin and the proportion of red cells in the total blood volume (hematocrit). Also, this analysis helps to detect abnormalities in the shape or size of red blood cells. In a healthy person, red cells look almost the same and have only minimal differences in shape or size. However, with a deficiency of vitamin B12, folic acid, iron, as well as other disorders, the size and shape of red blood cells can differ significantly from each other.

If the concentration of red blood cells and / or the amount of hemoglobin in the blood falls below normal, this indicates anemia. This disorder is characterized by symptoms such as fatigue and general weakness. Very rarely, red cells exceed the norm, in which case the person develops a disorder called erythrocytosis or polycythemia. In extreme cases, these conditions can prevent blood from passing through small veins and arteries.

Platelets

Complete blood count counts the number of platelets and also allows you to estimate their size. Platelets are special cell fragments that play a critical role in the blood clotting process. A person with a low platelet count is at increased risk for excessive bleeding and bruising. If the platelet count is higher than normal, the patient is at risk for excessive blood clotting.

How to decipher the complete blood count?

After the person has performed the analysis and the laboratory has conducted the study, he is given a form with the results. On it, the patient sees a table with norm indicators, with which doctors compare the figures obtained after the study. In order to get a rough picture of what is happening in the body, compare the results of the analysis with the tables below.

White blood cells (leukocytes)

Red blood cells (erythrocytes)

901 57

Possible causes for elevated values ​​

Platelets 5

Values ​​

Possible causes for low values ​​

Possible causes for high values ​​

Total platelet count

Viral infection (mononucleosis, hepatitis, measles),

Autoimmune platelet disease,

Medications (paracetamol, quinidine, sulfa drugs),

Cirrhosis,

Autoimmune diseases,

Sepsis,

Lake emia, lymphoma,

Myelodysplasia,

Radiation or chemotherapy.

Rheumatoid arthritis, lupus, inflammatory bowel disease,

Iron deficiency anemia,

Hemolytic anemia,

Myeloproliferative disorder (example: essential thrombocythemia),

Cancer of the lung, ovary, stomach or intestines, breast, lymphoma.