Leukemia is a cancer that occurs in blood cells. There are several types of leukemia and these are classified by how quickly they progress and which cells they affect.
The types include:
- Acute myeloid leukemia - occurs in both children and adults.
- Acute lymphocyte leukemia - the most common type seen in children, but also seen in adults over 65.
- Chronic myelogenous leukemia - occurs mostly in adults.
- Chronic lymphocytic leukemia - most often seen in people over age 55, can affect younger adults, but almost never seen in children.
In the case of leukemia, one blood cell goes awry and the body produces large numbers of this cell. In most cases the cell that goes awry is the white blood cell. When looked at under a microscope, these abnormally produced cells look different then the healthy cells and do not function properly. The body continues to produce these abnormal, non-functional cells, leaving little space for healthy cells. This imbalance of healthy and unhealthy cells is what causes the symptoms of leukemia.