Anemia, like any other useful sign of disease, is most efficiently corrected when therapy is directed at the specific pathological process or deranged physiological mechanism responsible for its development. The administration of a blood transfusion is the only direct treatment for anemia. It is effective in elevating the hemoglobin concentration, although often only temporarily, in a wide variety of disease states, even when it is employed without regard to the pathogenesis of the anemia. This is somewhat similar to the indication for an alcohol sponge bath for the patient with excessively high fever or the use of tracheotomy for acute laryngeal edema. All are useful, sometimes lifesaving, direct therapeutic attempts to relieve an abnormal sign of disease without altering the causative factors.
Anemia is usually defined as the state in which there is found a reduction in the concentration of hemoglobin, the number of erythrocytes, or the volume of packed