If you’ve got CLL, your body produces too many lymphocytes which don’t work properly.

It's a chronic condition so it tends to develop slowly over many years.

CLL is the most common leukaemia in adults. Men are twice as likely as women to get it. CLL is more common in older people (over 70). Children don’t get CLL, and it’s rare in young adults.

Read more about CLL

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We don’t know exactly what causes CLL, but some factors make it more likely, including:

• age
• sex
• family history
• ethnicity

Find more about causes of CLL

Many people with CLL are diagnosed after routine blood tests or a check-up.

People with CLL may experience extreme tiredness (fatigue), swollen lymph glands, night sweats and infection.

Find more about symptoms and diagnosis of CLL

You might not need treatment at first, especially if you don’t have any symptoms.

Some people may have chemotherapy or non-chemotherapy tablets and antibodies.

More information on CLL treatment and side effects

Although CLL can’t always be cured, it can be treated and many people will have a good quality of life.

Read more about the prognosis for CLL