Chronic lymphocytic leukemia (CLL)

Skip Navigation

Chronic lymphocytic leukemia (CLL) is a type of cancer that causes the body to produce large numbers of white blood cells (lymphocytes). These lymphocytes, called leukemia cells, cannot fight infection very well.

When leukemia cells build up in the blood and bone marrow, there is less room for healthy blood cells. This can cause infections, anemia, and easy bleeding.

CLL usually gets worse slowly. It is sometimes referred to as chronic lymphoblastic leukemia.




The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.