Chronic lymphocytic leukaemia (CLL)

Chronic lymphocytic leukaemia (CLL) is the most common type of leukaemia. About 2,700 people in the UK are diagnosed with it each year.

CLL usually develops very slowly and many people don't need treatment for months or years. However, some people need to have treatment straight away.

In people with CLL, the body makes too many white blood cells called lymphocytes. When examined under a microscope, the lymphocytes look normal, but they aren't fully developed (immature) and don't work properly. Over time, these abnormal lymphocytes build up in the lymphatic system and may cause large, swollen lymph nodes. They may also fill the bone marrow, reducing the number of normal white blood cells, red blood cells and platelets that the body can make.

Symptoms of chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) develops slowly and many people have no symptoms in the early stages.

It's often discovered by chance when a blood test is taken for another reason, such as before an operation or as part of a routine health check.

The signs and symptoms of CLL can include the following:

  • Feeling tired (fatigued) or unwell.
  • Frequent infections due to a shortage of healthy white blood cells that make antibodies and fight off infections. Infections may be more severe and take longer to clear.
  • Enlarged lymph nodes in the neck, armpits or groin, caused by a build-up of CLL cells. The swollen lymph nodes are usually painless.
  • Breathlessness, tiredness and headaches caused by too few red blood cells (anaemia).
  • Bruising and bleeding easily, which may happen if there aren't enough platelets in the blood. You may have nosebleeds that take a long time to stop (more than 10 minutes). You may get bruises in unexpected places and they may be much bigger than they should be.
  • A tender lump in the upper left-hand side of the abdomen caused by an enlarged spleen.
  • Severe sweating at night.
  • Weight loss.

*Information provided by Macmillan cancer support

At The Christie, leukaemias and other blood cancers are treated by the haematology and transplant unit.

Last updated: March 2023