Leukemia is a malignant disease (cancer) of the bone marrow and blood. It is characterized by the uncontrolled accumulation of blood cells. Leukemia is divided into four categories: myelogenous or lymphocytic, each of which can be acute or chronic. The terms myelogenous or lymphocytic denote the cell type involved. The major forms of leukemia are divided into four categories. Myelogenous and lymphocytic leukemia each have acute and chronic forms. The terms myelogenous or lymphocytic denote the cell type involved. 

Thus, the four major types of leukemia are:

  Acute Lymphocytic Leukemia

  Chronic Lymphocytic Leukemia

  Acute Myelogenous Leukemia

  Chronic Myelogenous Leukemia

Acute leukemia is a rapidly progressing disease that results in the accumulation of immature, functionless cells in the marrow and blood. The marrow often can no longer produce enough normal red blood cells, white blood cells and platelets. Anemia, a deficiency of red cells, develops in virtually all leukemia patients. The lack of normal white cells impairs the body's ability to fight infections. A shortage of platelets results in bruising and easy bleeding. Chronic leukemia progresses more slowly and allows greater numbers of more mature, functional cells to be made. Chronic leukemia progresses slowly and permits the growth of greater numbers of more developed cells. In general, these more mature cells can carry out some of their normal functions.

For more information, please visit the following web sites:

 http://www.leukemia-lymphoma.org

  http://www.intl.elsevierhealth.com/journals/lere

  http://leukemia-web.org