Mean Corpuscular Volume (MCV)

Mean corpuscular volume, or MCV, is a measurement of red blood cell size.

A normal MCV range is roughly 80–100 fl .

If someone's MCV level is below 80 fl, they will likely develop or have microcytic anemia. A low MCV (called microcytosis ) means red blood cells are small (RBC). A low MCH value typically indicates the presence of iron deficiency anemia. Iron is important for the production of hemoglobin.

MCV is used to classify anaemia as either microcytic, normocytic or macrocytic. A diagnosis of anaemia is based on haemoglobin levels less than 13 g/dl in males and 12 g/dl in females, and the MCV value can be used to classify anaemia as either microcytic, normocytic or macrocytic In microcytic anaemia, the average erythrocyte volume is smaller than normal, generally under 80 fl, and this finding is commonly observed in cases of chronic iron‐deficient anaemia, anaemia of chronic disease and thalassemias. Macrocytic anaemia is characterized by elevated MCV (generally over 100 fl) and is subcategorized as megaloblastic or non‐megaloblastic. Megaloblastic anaemia is caused by impaired DNA synthesis and commonly occurs in folate deficiency and vitamin B12 deficiency, while non‐megaloblastic anaemia occurs due to hepatic insufficiency, chronic alcoholism and rare congenital diseases.

By itself, large red blood cells (macrocytosis) do not cause any symptoms. However, they can help provide information about underlying health conditions. MCV values greater than 100 fl in patients with liver disease almost invariably indicate alcohol-related disease. If the MCV goes up to an extreme of 125, it may indicate vitamin B12, folate deficiencies, or cold agglutinin disease. A higher MCV value indicates that the red blood cells are larger than the average size.