Chronic lymphocytic leukaemia

About chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia is a type of cancer that affects the white blood cells and tends to progress slowly over many years.

It mostly affects people over the age of 60 and is rare in people under 40. Children are almost never affected.

In chronic lymphocytic leukaemia (CLL), the spongy material found inside some bones (bone marrow) produces too many white blood cells called lymphocytes that aren’t fully developed and don’t work properly.

Over time this can cause a range of problems, such as an increased risk of picking up infections, persistent tiredness, swollen glands in the neck, armpits or groin, and unusual bleeding or bruising.

CLL is different from other types of leukaemia, including chronic myeloid leukaemiaacute lymphoblastic leukaemia and acute myeloid leukaemia.

Symptoms of CLL

CLL doesn’t usually cause any symptoms early on and may only be picked up during a blood test carried out for another reason.

When symptoms develop, they may include:

  • getting infections often
  • anaemia – persistent tiredness, shortness of breath and pale skin
  • bleeding and bruising more easily than normal
  • a high temperature (fever)
  • night sweats
  • swollen glands in your neck, armpits or groin
  • swelling and discomfort in your tummy
  • unintentional weight loss

You should speak to your GP if you have any persistent or worrying symptoms. These symptoms can have other causes other than cancer, but it’s a good idea to get them checked out.

Read more about diagnosing CLL and complications of CLL.

Treatments for CLL

As CLL progresses slowly and often has no symptoms at first, you may not need to be treated immediately.

If it’s caught early on, you’ll have regular check-ups over the following months or years to see if it’s getting any worse.

If CLL starts to cause symptoms, or isn’t diagnosed until later on, the main treatments are:

  • chemotherapy – where medication is taken as a tablet or given directly into a vein is used to destroy the cancerous cells
  • a stem cell or bone marrow transplant – where donated cells called stem cells are transplanted into your body so you start to produce healthy white blood cells

Treatment can’t usually cure CLL completely, but can slow its progression and lead to periods where there are no symptoms. Treatment may be repeated if the condition comes back.

Read more about treating CLL.

Outlook for CLL

The outlook for CLL depends on how advanced it is when it’s diagnosed, how old you are when diagnosed, and your general health.

Younger, healthier people who are diagnosed when CLL is still in the early stages generally have the best outlook.

Although it can’t normally be cured, treatment can help control the condition for many years.

Causes of CLL

It’s not clear what causes CLL. There’s no proven link with radiation or chemical exposure, diet or infections. You can’t catch it from anyone else or pass it on.

However, having certain genes can increase your chances of developing CLL. You may be at a slightly higher risk of it if you have a close family member with it, although this risk is still small.

Diagnosing chronic lymphocytic leukaemia

Most cases of chronic lymphocytic leukaemia (CLL) are detected during blood tests carried out for another reason.

However, you should speak to your GP if you have worrying symptoms of CLL, such as persistent tiredness, unusual bleeding or bruising, unexplained weight loss or night sweats.

Your GP may:

  • ask about your symptoms and your medical and family history
  • carry out a physical examination to check for problems such as swollen glands and a swollen spleen
  • send off a blood sample for testing

If your GP thinks you could have CLL, you’ll be referred to a hospital doctor called a haematologist, a specialist in blood disorders, for further tests.

Blood tests

The main test used to help diagnose CLL is a type of blood test called a full blood count.

This is where the number and appearance of the different blood cells in a sample of your blood are checked in a laboratory.

An abnormally high number of unusual white blood cells (lymphocytes) can be a sign of CLL. A detailed examination of these cells can usually confirm the diagnosis.

X-rays and scans

You may also have:

These tests can check for problems caused by CLL, such as swollen glands or a swollen spleen, and help rule out other possible causes of your symptoms.

Bone marrow biopsy

Sometimes the haematologist may recommend removing a sample of your bone marrow (bone marrow biopsy) so they can examine it under a microscope to check it for cancerous cells.

The sample is removed using a needle inserted into your hip bone. Local anaesthetic is normally used to numb the area where the needle is inserted, although you may experience some discomfort during the biopsy.

The procedure will last around 15 minutes and you shouldn’t need to stay in hospital overnight. You may have some bruising and discomfort for a few days afterwards.

Lymph node biopsy

In some cases, removing and examining a swollen lymph gland can help confirm a diagnosis of CLL. This is known as a lymph node biopsy.

The gland is removed during a minor operation carried out under either local or general anaesthetic, where you’re asleep. You won’t usually need to stay in hospital overnight.

After the operation, you’ll be left with a small wound that will be closed with stitches.

Genetic tests

Tests may also be carried out on your blood and bone marrow samples to check for any unusual genes in the cancerous cells.

Identifying unusual genes in these cells can help your doctors decide how soon you should start treatment and which treatment is best for you.

Some treatments for CLL don’t work as well in people with certain abnormal genes in the affected cells.

Treating chronic lymphocytic leukaemia

Treatment for chronic lymphocytic leukaemia (CLL) largely depends on what stage the condition is at when it’s diagnosed.

You may just need to be monitored at first if it’s caught early on. Chemotherapy is the main treatment if it’s more advanced.

Treatment can often help keep CLL under control for many years.

It may go away after treatment initially (known as remission), but will usually come back (relapse) a few months or years later and may need to be treated again.

Stages of CLL

Doctors use stages to describe how far CLL has developed and help them determine when it needs to be treated.

There are 3 main stages of CLL:

  • stage A – you have enlarged lymph glands in fewer than 3 areas (such as your neck, armpit or groin) and a high white blood cell count
  • stage B – you have enlarged lymph glands in 3 or more areas and a high white blood cell count
  • stage C – you have enlarged lymph glands or an enlarged spleen, a high white blood cell count, and a low red blood cell or platelet count

Stage B and C CLL are usually treated straight away. Stage A generally only needs to be treated if it’s getting worse quickly or starting to cause symptoms.

Monitoring early-stage CLL

Treatment may not be needed if you don’t have any symptoms when you’re diagnosed with CLL.

This is because:

  • CLL often develops very slowly and may not cause symptoms for many years
  • there’s no benefit in starting treatment early
  • treatment can cause significant side effects

In these cases, you will normally just need regular visits to your doctor and blood tests to monitor the condition.

Treatment with chemotherapy will usually only be recommended if you develop symptoms, or tests show that the condition is getting worse.

Chemotherapy for more advanced CLL

Many people with CLL will eventually need to have chemotherapy. This involves taking medication to keep the cancer under control.

There are a number of different medicines for CLL, but most people will take 3 main medications in treatment cycles lasting 28 days.

These medicines are:

  • fludarabine – usually taken as a tablet for 3 to 5 days at the start of each treatment cycle
  • cyclophosphamide – also usually taken as a tablet for 3 to 5 days at the start of each treatment cycle
  • rituximab – given into a vein over the course of a few hours (intravenous infusion) at the start of each treatment cycle

Fludarabine and cyclophosphamide can usually be taken at home. Rituximab is given in hospital, and sometimes you may need to stay in hospital overnight.

A number of different medicines can also be tried if you can’t have these medicines, you’ve tried them but they didn’t work, or your CLL has come back after treatment.

These include bendamustine, chlorambucil, ibrutinib, idelalisib, obinutuzumab, ofatumumab and prednisolone (a steroid medication).

Side effects of treatment

The medicines used to treat CLL can cause some significant side effects, including:

Most side effects will pass once treatment stops. Let your care team know if you experience any side effects, as there are some treatments that can help.

Read more about the side effects of chemotherapy

Stem cell or bone marrow transplants

Stem cell or bone marrow transplants are sometimes used to try to get rid of CLL completely, or control it for longer periods.

Stem cells are cells produced by the spongy material found in the centre of some bones (bone marrow) that can turn into different types of blood cells, including white blood cells.

A stem cell transplant involves:

  • having high-dose chemotherapy and radiotherapy to destroy the cancerous cells in your body
  • removing stem cells from the blood or bone marrow of a donor – this will ideally be someone closely related to you, such as a sibling
  • transplanting the donor stem cells directly into one of your veins

This is the only potential cure for CLL, but it’s not done very often as it’s an intensive treatment and many people with CLL are older and not well enough for the benefits to outweigh the risks.

The initial treatment with chemotherapy and radiotherapy can place a significant strain on your body and cause troublesome side effects.

There’s also a risk of serious problems after the transplant, such as graft versus host disease. This is where the transplanted cells attack the other cells in your body.

Other treatments for CLL

There are also a number of other treatments that are sometimes used to help treat some of the problems caused by CLL, particularly if you can’t have chemotherapy or it doesn’t work.

These include:

  • radiotherapy to shrink enlarged lymph glands or a swollen spleen
  • surgery to remove a swollen spleen
  • antibiotics, antifungals and antiviral medications to help reduce your risk of picking up an infection during treatment
  • blood transfusions to provide more red blood cells and platelets (clotting cells) if you experience severe anaemia or problems with bleeding and bruising
  • immunoglobulin replacement therapy – a transfusion of antibodies taken from donated blood that can help prevent infections
  • injections of medication called granulocyte-colony stimulating factor (G-CSF) to help boost the number of white blood cells

You may also need additional treatment for any complications of CLL that develop.

Deciding against treatment

As many of the treatments for CLL can have unpleasant side effects that may affect your quality of life, you may decide against having a particular type of treatment.

This is entirely your decision and your treatment team will respect any decision you make.

You won’t be rushed into deciding about your treatment, and before making a decision you can talk to your doctor, partner, family and friends.

Pain relief and nursing care will still be available as and when you need it.

Complications of chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) can sometimes cause a number of further complications.


People with CLL usually have a weakened immune system and are more vulnerable to infections because they have a lack of healthy, infection-fighting white blood cells.

Treatment with chemotherapy can also further weaken the immune system.

If you have CLL, it’s a good idea to:

  • report any possible symptoms of an infection to your GP or care team immediately – things to look out for include a high temperature (fever), aching muscles, diarrhoea or headaches
  • ensure your vaccinations are up-to-date – speak to your GP or care team for advice about any additional vaccines you might need, as some aren’t safe if you have a weak immune system
  • avoid close contact with anyone who has an infection – even if it’s an infection to which you were previously immune, such as chickenpox

You may also be prescribed regular doses of medications such as antibiotics to help reduce the risk of infection.

Richter’s syndrome

In up to 1 in every 20 people with CLL, the condition will change to become very similar to an aggressive form of non-Hodgkin lymphoma. This is called Richter’s transformation or Richter’s syndrome.

Symptoms of Richter’s syndrome include:

  • sudden swelling of your lymph glands
  • a high temperature (fever)
  • night sweats
  • unintentional weight loss
  • tummy (abdominal) pain

Richter syndrome is usually treated with a combination of chemotherapy and other powerful medicines.

The Cancer Research UK website has more information on Richter’s syndrome.

Autoimmune haemolytic anaemia

Around 1 in every 10 people with CLL will develop a condition called autoimmune haemolytic anaemia.

This is where the immune system starts to attack and destroy red blood cells. It can cause severe anaemia, making you feel breathless and easily tired.

It’s usually treated with steroid medication

Psychological effects

Being diagnosed with CLL can be very distressing and difficult to take in at first, particularly as it can’t necessarily be cured and you may be advised to wait for it to get worse before starting treatment.

Having to wait years to see how the condition develops can also be very stressful and make you feel anxious or depressed. Speak to your GP or care team if you’re finding it difficult to cope.

You may also find it useful to talk to other people who are living with leukaemia. Your GP or care team will be able to provide you with the details of support groups in your area.

Macmillan Cancer Support provides an excellent level of help and support. Their helpline number is 0808 808 00 00, Monday to Friday, 9am to 8pm.

Causes of chronic lymphocytic leukaemia

It’s not known what causes most cases of leukaemia. However, there are many risk factors that are known to increase your chances of getting chronic lymphocytic leukaemia.

Risk factors for chronic lymphocytic leukaemia include:

  • having a family history of the condition
  • being of European, American or Australian origin
  • having certain medical conditions
  • being male 

Family history

In some cases, chronic lymphocytic leukaemia appears to run in families. It’s thought that an inherited gene mutation (change to a gene) could increase your susceptibility to developing the condition. This means there may be certain genes in your family that make it more likely that you’ll develop chronic lymphocytic leukaemia.

More research is needed, but having a parent or sibling (brother or sister) with chronic lymphocytic leukaemia slightly increases your chances of also developing the condition.


Chronic lymphocytic leukaemia most commonly affects people of European, American and Australian origin.

It’s rare in people from China, Japan and South East Asia, and it affects more white people than black people. It’s not known why the condition affects people of some ethnic backgrounds and not others.

Other medical conditions

Research has shown that having certain medical conditions slightly increases your chances of developing chronic lymphocytic leukaemia. These conditions include:

However, rather than causing chronic lymphocytic leukaemia, some of these conditions may occur as a result of having lowered immunity during the early stages of the condition.

Having a lowered immunity due to having a condition such as HIV or AIDS, or taking immunity lowering medication following an organ transplant can also increase your risk of developing chronic lymphocytic leukaemia.

Radiation exposure

Exposure to radiation is known to increase the risk of getting other types of leukaemia, but it’s not been linked specifically to chronic lymphocytic leukaemia.

The Cancer Research UK website has more information about the risk factors for chronic lymphocytic leukaemia.

Sex and age

For reasons that are unclear, men are around twice as likely to develop chronic lymphocytic leukaemia than women. The risk of developing leukaemia also increases as you get older.

Last updated:
03 July 2024

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