MCV Blood Test High: What Could Be Causing It?

MCV blood test high? An elevated MCV means your red blood cells are larger than average, but the number by itself does not tell you what is causing the change.

MCV stands for mean corpuscular volume and is one of the measurements included in a complete blood count. An MCV above about 100 fL is generally considered high, although the exact reference range can vary slightly between laboratories.

Why can the MCV become elevated?

A high MCV does not automatically mean that you have anemia or a serious disease. Instead, it gives your doctor a clue about what may be affecting your red blood cells. The result is interpreted together with your hemoglobin level, the rest of the blood count, your medical history, medications, and sometimes additional laboratory tests.

Common causes of a high MCV

• Vitamin B12 or folate deficiency.

• Alcohol use or medications that interfere with normal red blood cell development.

• Liver disease or an underactive thyroid.

• A rise in young red blood cells after bleeding or increased destruction of red blood cells.

• Less commonly, a disorder affecting the bone marrow.

What might your doctor check next?

Depending on your other results and medical history, your doctor may check vitamin B12 and folate levels, a reticulocyte count, a peripheral blood smear, thyroid tests, or liver tests. If the MCV remains unexplained, particularly when other blood counts are abnormal, additional evaluation may be appropriate.

The important point is that the MCV is a clue rather than a diagnosis. One mildly elevated result is not necessarily alarming, but a persistent elevation is worth discussing with your healthcare professional so the underlying cause can be identified.

This article and video are for educational purposes only and are not a substitute for individual medical advice, diagnosis, or treatment.