A common form of anemia is that occurring in association with various chronic infections and in a variety of chronic systemic diseases. As a rule the anemia is not severe, although the anemia associated with chronic renal insufficiency (defective functioning of the kidneys) may be extremely so. Most normocytic anemias appear to be the result of impaired production of red cells, and in renal failure there is a deficiency of erythropoietin, the factor in the body that normally stimulates red cell production.
In these states, the life span of the red cell in the circulation may be slightly shortened, but the cause of the anemia is failure of red cell production. The anemia associated with chronic disorders is characterized by abnormally low levels of iron in the plasma and excessive quantities in the reticuloendothelial cells (cells whose function is ingestion and destruction of other cells and of foreign particles) of the bone marrow. Successful treatment depends on eliminating or relieving the underlying disorder.