Anemias excluding cobalamin and folate deficiencies.

Anemias are one of the commonest maladies affecting humans. They result from either a failure of production by the bone marrow (hypoproliferative), or from premature destruction or loss (hyperproliferative) of red cells. Hypoproliferative anemias typically result from deficiencies of essential nutrients, stem cell abnormalities or deficiency, and infiltrative processes of the bone marrow. In the hyperproliferative forms, the bone marrow function is normal and anemia results from bleeding or shortened erythrocyte lifespan due to hemoglobinopathies, red cell enzyme disorders, membrane defects, or external factors such as antibodies, trauma, or heat injury. The etiology of anemia is frequently obvious, but when obscure, a systematic diagnostic approach frequently yields the answer. It is important to realize that anemias are usually a consequence of another disease process, which must be identified. Without correction of the underlying disease process, the treatment is likely to fail.