Mean Corpuscular Volume Test

The average volume or size of red blood cells in a blood sample is referred to as Mean Corpuscular Volume (MCV). The MCV blood test is often a part of the Complete Blood Count (CBC) test and it’s also commonly known as CBC with Differential. Corpuscular means blood cells and there are mainly 3 types - red blood cells, white blood cells and platelets. Red blood cells (erythrocytes) or RBCs carry oxygen from the lungs to every cell in our body. The cell metabolism depends upon the oxygen it receives. The RBCs which carry oxygen may be too small or too large and this can cause blood disorders or other medical conditions. The MCV blood test together with CBC test is done as part of routine screening of any blood disorder and health check- ups. A person complaining of fatigue, breathlessness, cold hands and feet, pale skin and unusual bleeding may need to undergo the MCV blood test.

The MCV blood test requires no special preparation. Visit your doctor if you experience any symptoms common to being anaemic. Discuss your health condition and any current medication. The doctor may advise you to discontinue current medication and recommend a MCV test together with other blood test like CBC. Take note of the doctor’s instructions. Remember to wear sleeveless or short sleeve dress to allow easy collection of blood sample.

The MCV parameter is the key to good health. Any abnormalities in its levels indicates the following -

• If normal MCV is detected, then it indicates normocytic (normal average RBC size).
• If low MCV is detected, then it indicates microcytic (small average RBC size). Anaemia and thalassemia are common blood disorders in such case.
• If high MCV is detected, then it indicates macrocytic (large average RBC size). Deficiency of vitamin B12 and folic acid, liver disorder, anaemia and hypothyroidism are commonly caused.

The MCV blood test is like other regular blood tests. You will be made to sit comfortably and your arm will be made to rest on a supportive prop. A qualified phlebotomist will tie a tourniquet on your upper arm to locate the vein. An alcohol based antiseptic is applied at the needle spot. A disposable needle is then gently pushed into the vein and the tourniquet is released. Blood sample is drawn and stored into labelled EDTA vials for laboratory tests. The MCV blood test is successfully accomplished in less than 5 minutes.