A patient with microcytic anemia and heavy menses. Most likely diagnosis?

• A. Iron deficiency anemia
• B. Aplastic anemia
• C. Thalassemia
• D. Sideroblastic anemia

Answer: (A)

Heavy menstrual bleeding can cause ongoing iron loss, leading to iron deficiency anemia. Iron is essential for making hemoglobin, so when stores are depleted, red blood cells become smaller and paler—the hallmark microcytic, hypochromic picture. In this context, the most likely diagnosis is iron deficiency anemia.

Aplastic anemia would present with low counts of all blood cell lines (pancytopenia) and usually not tied to bleeding history. Thalassemia is a congenital microcytic anemia and typically isn’t driven by iron loss from menses; iron studies may be normal or show inappropriate iron handling. Sideroblastic anemia involves dysfunctional iron utilization with usually iron overload and ring sideroblasts, not the pattern you’d expect with menstrual blood loss.