Chronic lymphocytic leukaemia (CLL) is a type of blood cancer. It affects the blood and bone marrow. CLL affects the white blood cells called lymphocytes. It tends to develop very slowly.

There are different types of leukaemia and the treatment you need depends on which type you have. 

What is chronic lymphocytic leukaemia (CLL)?

Chronic lymphocytic leukaemia (CLL) is a cancer that affects the white blood cells called lymphocytes. It tends to develop very slowly. 

Symptoms of chronic lymphocytic leukaemia (CLL)

Symptoms of CLL can include swollen glands, weight loss and infections that don't get better. Many people with CLL don't have any symptoms.

Getting diagnosed with chronic lymphocytic leukaemia (CLL)

You usually start by seeing your GP and they might refer you to a specialist and organise tests. Find out more about tests and screening for CLL. 

Survival for chronic lymphocytic leukaemia (CLL) RF Change test!

Survival depends on many factors including the stage of your CLL and whether there are changes in certain genes. 

Treatment for chronic lymphocytic leukaemia (CLL)

If you have very early stage CLL you may not need treatment straight away.

Staging chronic lymphocytic leukaemia (CLL)

The stage means how far your chronic leukaemia has developed. There are 3 stages - A, B and C. 

Research and clinical trials into chronic lymphocytic leukaemia (CLL)

Research is looking into the causes and treatment of CLL. Find out about the latest UK research and how you can take part in trials.

Living with chronic lymphocytic leukaemia (CLL)

There is support available to help you cope with a diagnosis of CLL.

Risks and causes of chronic lymphocytic leukaemia (CLL)

We don’t know what causes most cases of CLL. But there are some factors that may increase your risk of developing it.

Last reviewed: 
25 Sep 2024
Next review due: 
25 Sep 2027

Page Credits

These sections have been written, reviewed and updated by Cancer Research UK’s Patient Information Web Team. Thanks to the expert medical professionals and people affected by cancer who have helped to review this information.

Dr Piers Patten, Clinical Senior Lecturer and Honorary Consultant Haematologist

Our lay reviewers