The Common Anemias

LIKE fever, anemia is a sign of disease. It has many causes, most of them quite rare. In this article, advances in our understanding of only three of the most common forms of anemia will be discussed. These are thalassemia, iron deficiency, and, for want of a better name, "the anemia of chronic disease." I do not wish to slight either the importance or the interesting nature of advances in the understanding of other anemias. However, such disorders as sickle cell anemia; the hemolytic anemias caused by membrane defects of red blood cells, enzyme deficiencies, or antibodies; the megaloblastic anemias; the myelodysplastic anemias; and paroxysmal nocturnal hemoglobinuria will not be discussed here. The collective frequency with which these disorders occur does not approach that of thalassemia, iron deficiency, and the anemia of chronic disease (Fig 1). THE THALASSEMIAS The inclusion of thalassemia among the most common of the anemias may