by Scholten A


Chronic lymphocytic leukemia (CLL) is a cancer of the blood and bone marrow. With CLL, the bone marrow makes too many white blood cells called lymphocytes. This crowds out other blood cells. It can lead to problems with infections and bleeding.

CLL may be slow growing for many years and not cause problems. Some forms of CLL may be more serious.

White Blood Cells
White Blood Cells
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Cancer happens when cells divide without control or order.

The exact cause of CLL is not known. It is likely a combination of genes and environment.

Risk Factors

CLL is more common in older adults. Other things that raise the risk are:

  • A family history of blood cancer
  • Living or working on a farm
  • Exposure to chemicals such as benzene and Agent Orange


People with CLL often do not have symptoms for a few or many years. When symptoms happen, they may be:

  • Tiredness and problems exercising
  • Fever, night sweats
  • Weight loss without trying
  • Painless swelling in the neck, underarms, stomach, or groin
  • Paleness
  • Easy bruising or bleeding
  • Pain or a feeling of fullness below the ribs
  • Bone pain


The doctor will ask about your symptoms and health history. A physical exam will be done. The doctor may also check for swelling of the liver, spleen, or lymph nodes.

Tests may include:

  • Blood tests
  • Bone marrow biopsy—to remove and test a sample of bone marrow
  • Lumbar puncture —to test the fluid around the brain and spinal cord for cancer
  • Cytogenetic analysis—to look for changes in white blood cells
  • Immunophenotyping—to check the type of leukemia

The exam and test results are used to diagnose the cancer. They are also used for staging. Staging outlines how far and fast cancer has spread.

Imaging tests will look at other body structures to see if the cancer has spread. Tests may be:


CLL cannot be cured. However, ongoing treatment can help many people to live for a long time.

Treatment depends on the person's age, health, and the type and stage of CLL. For low-risk CCL with no symptoms, the doctor may just monitor the disease. Some people go for many years before strong treatment is needed.

When symptoms appear, a combination of treatments may be used. They may include:

  • Chemotherapy by mouth, injection, or IV—to kill cancer cells
  • Monoclonal antibody therapy—to help the body fight cancer cells
  • Stem cell transplant—blood cells given from a donor
  • Supportive care, such as:
    • Medicines to prevent side effects
    • Antibiotics and anti-viral drugs—to prevent infections
    • Blood transfusions—to replace low numbers of blood cells
  • A splenectomy—surgery to remove the spleen, if it is causing problems
  • External radiation therapy—sometimes used to treat other problems, such as with the spleen or lymph nodes


There are no current guidelines to prevent CLL.


American Cancer Society 

The Leukemia and Lymphoma Society 


Canadian Cancer Society 

Provincial Health Services Authority 


Chronic lymphocytic leukemia (CLL). American Cancer Society website. Available at: Accessed March 23, 2021.

Chronic lymphocytic leukemia (CLL)/small lymphocytic leukemia (SLL). EBSCO DynaMed website. Available at: . Accessed March 23, 2021.

General information about chronic lymphocytic leukemia. National Cancer Institute website. Available at: Accessed March 23, 2021.

Hallek M, Shanafelt TD, Eichhorst B. Chronic lymphocytic leukaemia. Lancet. 2018;391(10129):1524-1537.

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