Also called: CLL, CML

Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work.

Leukemia can develop quickly or slowly. Acute leukemia develops quickly. Chronic leukemia develops slowly. It usually occurs during or after middle age. At first, the abnormal cells still function. Eventually, however, the disease gets worse. It might cause

• Infections
• Fever
• Weight loss
• Swollen lymph nodes
• Tiredness

You can often control chronic leukemia, but it is hard to cure. You might not need immediate treatment if you don't have symptoms. Treatments may include chemotherapy, radiation, biological therapy, surgery or stem cell transplantation.