Microcytic Anemia

THE MICROCYTIC ANEMIAS ARE THOSE CHARACTERIZED BY THE PRODUCTION of red cells that are smaller than normal. The small size of these cells is due to decreased production of hemoglobin, the predominant constituent of red cells (Fig. 1). The causes of microcytic anemia are a lack of globin product (thalassemia), restricted iron delivery to the heme group of hemoglobin (anemia of inflammation), a lack of iron delivery to the heme group (iron-deficiency anemia), and defects in the synthesis of the heme group (sideroblastic anemias). This review highlights new aspects of the most common microcytic anemias: thalassemia, anemia of inflammation, and iron-deficiency anemia.