A packed cell volume (PCV) test is a routine blood test that analyses and measures the proportion of red blood cells in a blood sample. It is also alternatively known as a hematocrit test and is expressed as a percentage of packed RBCs by volume in a blood sample, from which the amount of RBCs present in the body can be inferred.

What is a PCV test?

A packed cell volume or PCV test is a serological test that provides a comprehensive assessment of the percentage of red blood cells. The purpose of a PCV test is to assess the blood volume and the oxygen-carrying capacity of the red blood cells. A PCV test is generally ordered alongside a routine blood test (complete blood count).

When should I get the PCV test?

A PCV test is typically performed as part of a complete blood count (CBC) test or during routine blood work. It may be specifically recommended for diagnosing and monitoring certain medical conditions such as anaemia, dehydration, and polycythemia. A doctor may also order a PCV test to assess the effectiveness of treatments related to blood conditions like anaemia.

What happens during the PCV test?

A PCV test is a blood test, so it involves collecting a blood sample and sending it to the laboratory for testing. 

Procedure for PCV test

The PCV test is performed in a laboratory by centrifuging a blood sample. During centrifugation, the blood cells settle at the bottom of the centrifuge tube while the plasma rises to the top. The percentage of red blood cells in the blood sample can be determined by measuring the height of the packed RBCs at the bottom in relation to the total height of the sample.

Uses of PCV test

A PCV test primarily measures the percentage of RBCs in a sample of blood. It is usually performed to diagnose or rule out blood conditions such as anaemia or polycythemia in patients. Doctors may also recommend the PCV hematocrit test to evaluate the response to blood transfusions or determine the effectiveness of treatments for certain blood conditions. Overall, a PCV test provides a thorough assessment of a person's health and their risk of developing certain medical conditions.

How to prepare for the PCV test?

For a PCV blood test, there are no dietary restrictions as it falls under routine blood work. Therefore, patients do not require fasting before the sample is collected. During blood collection, the phlebotomist locates a vein in the arm and cleans the area with an alcoholic antiseptic liquid. Subsequently, the sample is collected using a sterile needle and then sent to the lab for analysis.

Values of PCV Test Results

PCV test results are expressed in percentages. If the PCV blood test shows a reading of 50%, it means that in 100 ml of blood, red blood cells occupy 50 ml by volume. Any increase or decrease in this reading may indicate various health conditions and problems, some of which may be chronic.

The PCV test normal range varies depending on gender, age, and other factors. 

Having PCV levels below or above the recommended levels may mean different things for different people depending upon their symptoms and testing requirements.

Low PCV in blood test

If the PCV level is lower than the normal recommended range, it may be due to a number of conditions. Anaemia and blood loss are very commonly associated with low PCV levels. Anaemia may be caused by various conditions, including vitamin deficiency, mineral deficiency, or chronic illness. Blood loss can result from trauma or surgery, and it may also be due to chronic conditions such as gastrointestinal bleeding or menstrual disorders. Several factors can contribute to low PCV levels in a blood test:

• Vitamin B12 deficiency
• Kidney disorders
• Mineral deficiency
• Inflammatory diseases
• Hemolysis

High PCV level

A high PCV in a blood test is often caused by conditions such as dehydration or polycythemia. Dehydration is characterised by a loss or deficiency of bodily fluids, which can result from various reasons, including inadequate fluid intake or certain medications. Polycythemia is a condition where there is an excess of red blood cells compared to the PCV blood test normal range, and it can occur due to various factors, including genetics and smoking. If a person has polycythemia, it may increase their risk of stroke, blood clots, and other complications. High PCV levels may also indicate lung disease.

Conclusion

A PCV test or hematocrit test is routine blood work conducted to assess the amount of RBCs present in a blood sample. This test can be used for diagnosing certain blood disorders or for monitoring the overall health of patients.

FAQs

1. What does it mean to have low PCV?

Ans. Having low PCV levels in a blood test may indicate several underlying health conditions, such as anaemia or vitamin and mineral deficiencies. However, based on the test report, along with additional diagnostic tests and the symptoms experienced, the doctor can make a correct diagnosis of the condition.

2. What causes low PCV levels?

Ans. Low PCV levels in a blood test can be caused by various conditions, including anaemia, blood loss, chronic illnesses, certain medications, or nutritional deficiencies.

3. What is meant by a high PCV level?

Ans. A high PCV level in a PCV blood test may indicate higher-than-normal levels of RBCs in the blood, which can be caused by various factors, including environmental influences and blood disorders such as polycythemia.

4. What is the cause of high PCV levels in a blood test?

Ans. If the PCV level in a hematocrit blood test is high, it may be due to factors such as dehydration, polycythemia, smoking, or certain medications.

5. What is the cost of a PCV test?

Ans. The cost of a PCV blood test typically ranges between Rs. 100 and Rs. 200.