- Chronic lymphocytic leukaemia is a rare type of cancer that affects the blood and bone marrow.
- It usually develops very slowly and does not always need to be treated straight away.
- Chronic lymphocytic leukaemia cannot usually be cured, but it can be managed with treatment.
- It's more common as you get older. It's very rare in people under 40.
- It's not clear what causes chronic lymphocytic leukaemia, but having a close family member who's had it may mean you have a slightly higher risk.
What is chronic lymphocytic leukaemia?
Page last reviewed: 10 September 2026
Next review due: 10 September 2029