Question

A patient has Hb 9 g/dL, MCV 68 fL and a low serum ferritin. The most likely type of anemia is:

• A. Iron deficiency anemia
• B. Megaloblastic anemia
• C. Aplastic anemia
• D. Hemolytic anemia

Hint:

Low MCV + low ferritin is the classic iron-deficiency signature.

Answer 1

The Correct Option is A

Step 1: Classify by MCV. An MCV of 68 fL (normal ~80-100 fL) indicates a microcytic anemia. Causes include iron deficiency, thalassemia, anemia of chronic disease, and sideroblastic anemia.

Step 2: Use the ferritin. Serum ferritin is the key discriminator of iron stores. A low ferritin is essentially diagnostic of depleted iron stores, i.e., iron deficiency anemia. (Ferritin is high/normal in thalassemia and anemia of chronic disease.)

Step 3: Eliminate others. Megaloblastic anemia (B12/folate) is macrocytic (high MCV) - opposite picture, so option 2 is wrong. Aplastic anemia is typically normocytic/macrocytic with pancytopenia and normal-to-high ferritin (option 3 wrong). Hemolytic anemias are usually normocytic with raised reticulocytes, LDH and bilirubin, not low ferritin (option 4 wrong).

Key fact: Microcytic anemia (low MCV) with a low ferritin = iron deficiency anemia.