What Is CLL? Chronic Lymphocytic Leukemia, or CLL for short, is a type of cancer. CLL is the most common chronic leukemia in the United States. In people with CLL, too many abnormal white blood cells (known as lymphocytes) build up in the blood, bone marrow, spleen, and lymph nodes. Over time, these cells may crowd healthy cells, resulting in fewer normal blood cells and platelets.
Chronic Lymphocytic Leukemia (CLL) causes a slow increase in white blood cells called B lymphocytes, or B cells. Cancer cells spread through the blood and bone marrow, and can also affect the lymph nodes or other organs such as the liver and spleen. CLL eventually causes the bone marrow to fail. The cause of CLL is unknown. There is no link to radiation, cancer-causing chemicals, or viruses. This cancer mostly affects adults, around age 70. It is rarely seen under age 40. The disease is more common in Jewish people of Russian or East European descent.
Symptoms usually develop slowly over time. Many cases of CLL are detected by blood tests done in people for other reasons or who do not have any symptoms. Symptoms that can occur include:
- Abnormal bruising (occurs late in the disease)
- Enlarged lymph nodes, liver, or spleen
- Excessive sweating, night sweats
- Infections that keep coming back (recur)
- Loss of appetite or becoming full too quickly (early satiety)
- Unintentional weight loss