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We're here for you if you want to talk

0808 2080 888

[email protected]

We're here for you if you want to talk

0808 2080 888

[email protected]

Chronic lymphocytic leukaemia (CLL) is a slow-growing blood cancer that may not need treatment at first. When it does need treatment, there are many effective drugs that can keep the CLL under control.

A headshot of Erica, who has chronic lymphocytic leukaemia (CLL), wearing a thick knitted jumper smiling into the camera.

What is CLL?

CLL is a chronic (slow growing) blood cancer that affects cells called lymphocytes. When you have CLL, your body makes abnormal lymphocytes that grow too fast.
An older man wearing a white shirt and grey jumper is in consultation with his doctor. He is making eye contact and looks like he is asking a question.

Prognosis for CLL

CLL can't usually be cured, but it can be treated so you can continue to have a good quality of life.
Woman lying on sofa looking tired.

CLL symptoms and diagnosis

Many people with CLL are diagnosed after a routine blood test and won't haven’t noticed any symptoms, but others do.
A researcher wearing a facemask inspects a vial of blood on a table with other vials.

Testing for CLL

You’ll have tests before and after diagnosis to confirm that you have CLL, monitor it, and monitor any treatment you may need.
A variety of pills

CLL treatment and side effects

When treatment is needed, you will be offered options that are right for you and your situation.
A woman with short grey hair sitting on the sofa in a living room, on a video call with someone on her laptop.

Active monitoring (watch and wait)

Some people with CLL won't need treatment straight away, or even for months or years. This is called active monitoring, or watch and wait.
A man having chemotherapy in hospital

CLL and infection

CLL affects your immune system, so even if you don’t need treatment, you’re more likely to get infections.
An image of a nurse in uniform working at a hospital.

Clinical trials

You may be able to join a clinical trial as part of your treatment for CLL.

This information about chronic lymphocytic leukaemia is accredited with the PIF TICK, the UK's only quality mark for trusted health information.

Last review January 2026. Next full review due January 2029. We may make factual updates to the information between reviews.

We would like to thank Consultant Haematologists Dr Piers Patten and Dr Dima El-Sharkawi for checking the clinical accuracy of this information. Thank you also to Ann, David, Eirwen, Erica, John, Gerard, Johanna, Kate, Mel and Paul for supporting this project and sharing their experience of living with CLL.