Anemia may be defined as a deficiency in red blood cells or hemoglobin or both. Anemia is serious because of the impaired ability of the blood to carry oxygen. As a result the cells degenerate, especially those of the nervous system. This explains such early symptoms as disinterest, fatique, and loss of energy.

There are various kinds of anemia. For example, blood loss anemia is a result of hemorrhage or the chronic loss of blood. Although the bone marrow may be able to maintain a nearly normal red blood count, the iron stores of the body become progressively decreased. Accordingly, this type of anemia is marked not only by a decrease in the number of red blood cells but also by a severe drop in hemoglobin.

Iron deficiency anemia results from the insufficient intake of iron. Although the red cell count is usually nearly normal, the concentration of hemoglobin in each cell is reduced greatly, hence the expression hypochromic anemia. This condition is quite common and is treated successfully with iron compounds such as ferrous sulfate.

Hemolytic anemias involve excessive destruction of red blood cells. The more common forms include sickle cell anemia, erythroblastosis fetalis (Rh incompatibility). And poisoning from drugs and chemicals. Sickle cell anemia is a hereditary disease characterized by distorted red blood cells.

Pernicious anemia, which proves fatal if not treated, result from a deficiency of a so-called intrinsic factor normally present in the lining of stomach. Since this factor is needed for the absorption of vitamin B12 (the extrinsic factor), a deficiency will severely curtail the manufacture of red blood cells in the marrow. ( vitamin B12, material in the manufacture of red cells). The treatment of pernicious anemia is highly specific and calls for periodic shots of vitamin B12.

Aplastic anemia is a fatal condition steming from destruction of the bone marrow. The usual causes are drugs, poisons, and overexposure to x rays, gamma rays, or certain other forms of radiation.