Packed Cell Volume Test

The Packed Cell Volume test is also called the haematocrit test. It is used to diagnose anaemia, polycythaemia or dehydration in patients. Generally, the test is a part of a full blood count and is commonly carried out to monitor response to treatment, estimate need for blood transfusions, etc. Blood is a mixture of plasma and cells. The packed cell volume (PCV) test measures how much of the blood consists of cells. A PCV of 50% means 50 ml of cells are present in 100 ml of blood. If the number of red blood cells increases, the PCV also rises. It also increases as a result of dehydration.

This test does not require any special preparation. You must inform your doctor if you have any questions or anxiety regarding the test. Also, let your doctor know if you have been taking any medications, have any allergies or any underlying medical problems. You do not have to fast before taking this test.

A low PCV implies that the patient has low number of red blood cells and is suffering from anemia. The doctor may ask the patient to undergo further tests to determine underlying causes of anemia. Treatment will be given accordingly.

To carry out the test, blood is withdrawn from the arm using a needle. Before withdrawing blood, an elastic band will be wrapped around the arm to stop blood flow and to make veins visible. The site will be cleaned and a needle will be inserted. Once enough sample is obtained, the needle and elastic band will be removed and the needle site will be rubbed with cotton.