What is the Definition of Leukemia?
Article updated and reviewed by Corey Cutler, MD MPH FRCP(C), Instructor in Medicine, Harvard Medical School, Dana-Farber Cancer Institute on May 11, 2005. Leukemia is a malignant disorder (a form of cancer) that involves the bone marrow and blood systems. Leukemia results in the uncontrolled growth of abnormal (leukemic) white blood cells. As a result of the uncontrolled growth of leukemic cells in the bone marrow, there is inadequate space in the bone marrow for normal blood production (hematopoiesis) to occur. The lack of normal blood growth results in the lack of normal white blood cells (increasing the risk of infection), the lack of red blood cells (resulting in fatigue, weakness, and anemia) and the lack of normal platelet production (increasing the risk of bleeding). There are many different types of leukemia. Each of these types may appear with some, none, or all of the symptoms or signs described below.
