Low MCV (Mean Corpuscular Volume) means that the red blood cells (RBCs) are smaller than normal, a condition known as microcytosis or microcytic anemia. This typically indicates that the average size of red blood cells is below 80 femtoliters (fL)
. Common causes of low MCV include:
- Iron deficiency anemia, the most frequent cause, where there is insufficient iron to produce normal-sized RBCs
- Thalassemia, a genetic disorder leading to abnormal hemoglobin production and smaller RBCs
- Lead poisoning, which interferes with hemoglobin synthesis
- Chronic diseases causing impaired RBC production
- Sideroblastic anemia and other less common causes such as vitamin deficiencies, heavy alcohol consumption, and certain medications
Symptoms associated with low MCV/microcytic anemia may include:
- Fatigue and weakness
- Shortness of breath
- Dizziness
- Pale skin
- Hair loss and nail changes in some cases
Diagnosis and treatment:
Low MCV alone is not enough for a definitive diagnosis; it is interpreted
alongside other blood tests and clinical symptoms
. Treatment depends on the underlying cause, for example:
- Iron supplements and vitamin C for iron deficiency anemia, often over several months
- Specific therapies for chronic diseases, lead poisoning, or genetic conditions like thalassemia
In summary, low MCV indicates smaller-than-normal red blood cells, most commonly due to iron deficiency anemia or genetic conditions affecting hemoglobin, and requires further evaluation to determine the exact cause and appropriate treatment
