Britannica Sources used in this answer

How can the mean corpuscular volume help identify different types of anemia?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

blood disease Peripheral blood smear revealing histopathologic features indicative of a blast crisis in a case of chronic myelogenous leukemia (CML). Blast crisis occurs when one-fifth to one-third of the cells in the blood or bone marrow are immature blood cells, or blast cells. This phase of CML is characterized by fever, weakness, and an enlarged spleen.

The mean corpuscular volume (MCV) is a critical diagnostic index used to classify anemias based on the average size of red blood cells, which normally measure 82 to 92 cubic micrometres. By calculating the MCV, clinicians can categorize anemia into three primary morphological types:1

Macrocytic anemia: The MCV is higher than normal, indicating that circulating red blood cells are larger than average. This is often associated with impaired production, such as deficiencies in vitamin B12 or folic acid.12
Microcytic anemia: The MCV is lower than normal, reflecting smaller-than-average red blood cells. This includes hypochromic microcytic anemia, frequently caused by iron deficiency or thalassemia, where cells are also poorly filled with hemoglobin.12
Normocytic anemia: The MCV remains within the normal range, meaning there is no significant alteration in the size of the red blood cells, despite a decrease in their total number.12

Accurate measurement of the MCV, alongside the mean corpuscular hemoglobin concentration (MCHC), is essential for determining the underlying cause of anemia and ensuring appropriate treatment.1