The life span of a red blood cell is between 90 and 120 days. Old red blood cells are removed from the blood by the liver and spleen, and the iron is returned to the bone marrow to make new cells. The kidney is also essential in regulating the production of red blood cells. General Description Anemia is characterized by an abnormally low number of red blood cells in the circulatory system. The process of manufacturing, recycling, and regulating the number of red blood cells is complex and involves many parts of the body.
Malfunction can occur at any point in the process.
Some less common causes and types of anemia are included in the table below. Aplastic Anemia Fat cells replace bone marrow. Reduction in all types of blood cells. Formerly fatal, but now treatable. Symptoms in addition to standard anemia are bleeding in mucous membranes and skin, gingivitis, and shortness of breath.