RDW is increased in which microcytic anemia?

RDW is increased in which microcytic anemia?

• A. Sideroblastic anemia
• B. Anemia of chronic disease
• C. Iron deficiency anemia
• D. Thalassemia minor

Answer: (C)

RDW measures how much red blood cell sizes vary. In iron deficiency, as iron stores dwindle and new cells become smaller, you get a mix of normal and smaller cells, producing a wide range of sizes. That anisocytosis raises RDW. Other microcytic conditions tend to have more uniform cell sizes: thalassemia minor usually shows a normal RDW because cells are uniformly small; anemia of chronic disease often has normocytic or only mildly microcytic cells with a normal RDW. Sideroblastic anemia can show variability, but iron deficiency most characteristically presents with increased RDW.

RDW measures how much red blood cell sizes vary. In iron deficiency, as iron stores dwindle and new cells become smaller, you get a mix of normal and smaller cells, producing a wide range of sizes. That anisocytosis raises RDW. Other microcytic conditions tend to have more uniform cell sizes: thalassemia minor usually shows a normal RDW because cells are uniformly small; anemia of chronic disease often has normocytic or only mildly microcytic cells with a normal RDW. Sideroblastic anemia can show variability, but iron deficiency most characteristically presents with increased RDW.