It's not clear what causes chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia is rare, but it's more common:

• as you get older – it's very rare in people under 40
• if you're male
• if someone in your family has had it

It's unlikely that your symptoms are caused by cancer, but it's important to get symptoms of chronic lymphocytic leukaemia checked by a GP.