Mean corpuscular volume
Mean corpuscular volume (Erythrocyte mean cell volume, MCV) is a useful parameter of the red cell count produced by autoanalysers. It is expressed in femtoliters (fL).
The commonest causes of a low value are the microcytic anaemias of iron deficiency, thalassemia and sideroblastic anaemia. High values may reflect reticulocytes due to new blood formation as in haemolytic anaemia, macrocytic anaemia as due to folate or B12 deficiency, myxoedema or alcohol (and other drug) exposure. See anaemia for more details as to how MCV is used in clinical practice.