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Chronic lymphocytic leukaemia (CLL)

CLL is a type of leukaemia (blood cancer). 
CLL is usually a slow-growing cancer. 
About 200 people in Ireland are diagnosed with CLL each year. 

The main treatments for CLL are targeted therapies, chemotherapy and steroid therapy.

What is chronic lymphocytic leukaemia (CLL)?

CLL is a type of leukaemia (cancer of the blood). It is usually a slow-growing cancer of lymphocyte white blood cells.

CLL stops the white blood cells working properly to fight infection.

CLL also means that the lymphocytes don’t die off naturally at the end of their life span. The cells may build up in your lymph nodes and spleen, causing them to become swollen. They can also build up in your bone marrow, meaning there is not enough space for normal blood cells to develop. This causes problems with fighting infection, carrying oxygen and bleeding.

Many people with slow-growing CLL can live a normal life. Other people experience symptoms that affect their quality of life at different stages of their disease and treatment.

Small lymphocytic lymphoma (SLL)

 CLL and SLL both affect lymphocytes. They are different forms of the same disease. The difference between them is where the cancer is mainly found: 

  • CLL: Most of the cancer cells are in the blood and the bone marrow. The lymph nodes and spleen may be affected too.
  • SLL: Most of the cancer cells are in the lymph nodes.

If you have SLL and need more specific information, you can call our Support Line on 1800 200 700.

More information about a CLL diagnosis

More information about CLL treatment

Treatment for CLL includes targeted therapies, chemotherapy, steroid therapy and occasionally stem cell transplants. For more information about treatments for CLL, visit our treatment page. For specific information use the links below.

Coping with CLL treatment and side-effects

Looking for support?

Our cancer support section contains information and advice on coping with cancer for diagnosed patients and their loved ones.

Medical content updated from our Understanding Chronic Lymphocytic Leukaemia booklet (2023). Reviewed by Dr Johnny McHugh, Consultant Haematologist, Sinead Lawlor, Clinical Nurse Manager, Liz O'Connell, Haematology Nurse Coordinator and Anna Drynan Gale, Daffodil Centre Nurse.

Publications about CLL
Chronic lymphocytic leukaemia booklet
Chronic lymphocyctic leukaemia (CLL) booklet
Information for chronic lymphocytic leukaemia patients, including treatment and tips on living with a blood cancer.

For more information

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1800 200 700

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