Which term describes the condition where red blood cells are larger than normal?

• A. Iron-deficiency anemia
• B. Megaloblastic anemia
• C. Sickle cell anemia
• D. Pernicious anemia

Answer: (B)

Larger than normal red blood cells indicate macrocytosis, and when this occurs due to impaired DNA synthesis in the bone marrow, the condition is megaloblastic anemia. This typically happens from deficiencies of vitamin B12 or folate, which slow the maturation of RBCs and cause them to develop into abnormally large cells. In contrast, iron-deficiency anemia produces smaller cells, and sickle cell anemia features abnormally shaped, crescent-like cells rather than simply larger ones. Pernicious anemia is a common cause of B12 deficiency that can lead to megaloblastic changes, but the term that directly describes the oversized cells is megaloblastic anemia.