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 

These are discussed in more detail below.

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.

Ethnicity

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:

• pneumonia (chest infection) 
• sinusitis 
• shingles 
• autoimmune haemolytic anaemia
• long-term (chronic) osteoarthritis
• prostatitis (an inflamed prostate)

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.

Increased vulnerability to infections is one of the main complications of chronic lymphocytic leukaemia.

If you have chronic lymphocytic leukaemia, your immune system will be weakened due to a reduced number of healthy, infection-fighting white blood cells. Chemotherapy and other powerful cancer-killing medication also weaken the immune system.

Having a weakened immune system makes you more vulnerable to infection – if you develop an infection, it’s more likely to cause serious complications.

Due to the risk of infection, you should have a flu vaccination and a pneumococcal vaccination to protect against pneumococcal infections. Regular doses of antibiotics may also be recommended.

Report any possible symptoms of an infection to your GP or care team immediately. Prompt treatment may be needed to prevent serious complications developing.

Common symptoms of infection include:

• a high temperature (fever) of 38ºC (100.4ºF) or above
• headache

• aching muscles
• diarrhoea

• tiredness

Avoid contact with anyone who is known to have an infection, even if it’s an infection to which you were previously immune, such as chickenpox or measles. Your previous immunity to these conditions may be lower because of the leukaemia.

You should also ensure that all of your other vaccinations are up-to-date. Your GP or care team can give you more advice about this.

However there are some types of vaccine, known as “live” vaccines, that you won’t able to have, as they contains activated particles of the virus or bacteria they are designed to protect you against.

As your immune system will be weakened by the leukaemia and the treatment you receive, your risk of developing warts and verrucas will increase. They can also be more difficult to treat and, in rare cases, can develop into skin cancer.

Visit your GP immediately if you have a wart that changes colour or shape.

Richter syndrome

In a small number of people with chronic lymphocytic leukaemia (5% or less), 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 nodes
• a high temperature not caused by infection
• night sweats
• weight loss
• abdominal pain

Richter syndrome is treated with a combination of chemotherapy and rituximab.

For more information about Richter’s syndrome, see the Cancer Research UK website.

Autoimmune haemolytic anaemia

Around 10% of people with chronic lymphocytic leukaemia will develop autoimmune haemolytic anaemia, due to the breakdown of red blood cells. It’s caused by the production of an antibody that targets and destroys the red blood cells.

Anaemia can be severe and it may cause you to become breathless or easily tired. Autoimmune haemolytic anaemia is usually treated with steroids, although other types of medication may also be used.

Psychological effects

Being diagnosed with chronic leukaemia can be very distressing, particularly if your condition can’t be cured. At first, it may be very difficult to take in.

The situation can be made worse if you know your condition could become a serious problem later in life.

Having to wait many years to see how the leukaemia develops can be very stressful and may cause anxiety or depression.

If you’ve been diagnosed with leukaemia, talking to a counsellor or psychiatrist may help. Psychiatrists are doctors who specialise in treating mental health conditions.

Antidepressants or medication that reduces feelings of anxiety may also help you to cope better with the condition.

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).

Infertility

Many treatments that are used for chronic leukaemia can cause infertility (an inability to conceive). Infertility is often temporary, but can sometimes be permanent. Your treatment team will be able estimate your risk of infertility.

It may be possible to take steps to guard against the risk of infertility before your treatment begins. For example, sperm samples can be stored so that they can be implanted in an embryo at a later date.

In some cases, it may also be possible to store a fertilised embryo. After treatment has finished, the embryo can then be placed back into the womb.

Most cases of chronic lymphocytic leukaemia are discovered during unrelated routine blood tests.

However, you should visit your GP if you display the typical symptoms of leukaemia. They will ask about your symptoms, as well as your medical and family history.

Your GP will also carry out a physical examination to check for swollen glands, a swollen spleen and any signs of abnormal bleeding. You may also be asked to have a blood test.

Full blood count

If your GP suspects leukaemia, they’ll refer you to a haematologist (a doctor who specialises in conditions that affect the blood).

A blood sample will be taken and sent to a laboratory for a full blood count. Here, the different types of blood cells will be counted and the appearance of the cells checked.

An abnormally high number of lymphocytes (white blood cells) will suggest you have chronic lymphocytic leukaemia.

However, to confirm the diagnosis, the haematologist will need to carry out a procedure known as immunophenotyping. This involves examining the lymphocytes in detail to distinguish chronic lymphocytic leukaemia from other conditions that can also cause a high lymphocyte count.

This test is often carried out in a specialist laboratory and the results will usually be available in one to two weeks.

X-ray and ultrasound scan

You may also need to have some other tests, such as a chest X-ray, ultrasound scan or computerised tomography (CT) scan (see below).

A chest X-ray can be used to see whether there are any changes in your tissues or organs, and to rule out other possible causes of your symptoms.

Your doctor will also give you a physical examination to check the size of your spleen, and you may need to have an ultrasound scan to see the spleen in more detail.

Bone marrow biopsy

In some cases, the haematologist may want to look at a sample of your bone marrow.

A bone marrow biopsy involves taking a small sample of bone marrow to examine under a microscope. It is usually carried out under a local anaesthetic.

The haematologist will numb an area of skin at the back of your hip bone, before removing a sample of bone marrow using a needle. You may experience some discomfort during the procedure and have some bruising and discomfort in the area where the sample was taken for a few days afterwards.

The procedure will take around 15 minutes to complete and you shouldn’t need to stay in hospital overnight.

The bone marrow sample will be examined for cancerous cells. If these are present, the specific type of chronic leukaemia can also be determined.

Genetic tests

Genetic tests can also be carried out on blood and bone marrow samples. A test known as a fluorescence in situ hybridisation (FISH) test can be used to help identify abnormalities in the leukaemia genes.

Gene abnormalities are easy to identify because the affected genes glow. Doctors are able to use FISH to identify abnormal genes in the cells of about 80% of people with chronic lymphocytic leukaemia.

Identifying gene abnormalities in this way is very useful because it allows treatments to be targeted more effectively.

Further tests

A number of additional tests may be recommended to provide more information about the progress and extent of the leukaemia.

For example, if you’ve been diagnosed with chronic leukaemia, further biopsies may be carried out on any enlarged lymph nodes you have.

This is known as a lymph node biopsy and it can help determine whether the leuakemia is a more active variant, sometimes called a Richters transformation, or whether any other conditions are present.

Sometimes, your haemotologist may recommend that you have a CT scan, where a series of X-rays are taken and a computer is used to create detailed three-dimensional (3D) images of the inside of your body.

A CT scan can be used to check your lymph nodes and organs for abnormalities.

Leukaemia is cancer of the white blood cells. Chronic leukaemia tends to progress slowly over the course of many years.

Chronic leukaemia is classified according to the type of white blood cells affected by cancer.

This topic focuses on chronic lymphocytic leukaemia, which affects types of white blood cells called lymphocytes.

Read more about chronic myeloid leukamia.

Symptoms of chronic lymphocytic leukaemia

In its early stages, chronic lymphocytic leukaemia doesn’t usually cause any noticeable symptoms. As the condition develops, symptoms can include:

• repeated infections that occur over a short space of time
• tiredness due to a lack of red blood cells (anaemia)
• unusual bleeding and bruising
• fever
• night sweats
• bone pain
• weight loss
• swollen spleen
• swollen lymph nodes (glands)

What happens in chronic leukaemia

Bone marrow – the spongy material found inside bones – contains a specialised type of cell called stem cells.

These stem cells can develop into any of the three types of blood cell:

• red blood cells – which carry oxygen around the body
• white blood cells – which help fight infection
• platelets – which help stop bleeding

In leukaemia, the stem cells start overproducing white blood cells that aren’t fully developed. In chronic lymphocytic leukaemia, these are lymphocytes.

This overproduction of lymphocytes is at the expense of the other blood cells, and it’s this lack of red blood cells and platelets that can cause symptoms of anaemia, such as tiredness, as well as increasing the likelihood of excessive bleeding.

In some people with chronic lymphocytic leukaemia, the body’s immune system can start attacking red bloods and cause a different type of anaemia called haemolytic anaemia. This may require different treatment.

The white blood cells are also not properly formed, and these immature lymphocytes are much less effective at fighting bacteria and viruses, making you more vulnerable to infection.

Causes of chronic lymphocytic leukaemia

In most cases, it’s not known what causes leukaemia. However, there are some risk factors that may increase your chances of developing chronic leukaemia.

Known risk factors for chronic leukaemia include:

• having a family history of the condition
• being of European, American or Australian origin (it’s rare in people from China, Japan and South East Asia)
• having certain medical conditions, such as pneumonia (chest infection), sinusitis or shingles
• being male 

Read more about the causes of chronic lymphocytic leukaemia.

Diagnosing chronic lymphocytic leukaemia

Most cases of chronic lymphocytic leukaemia are discovered during unrelated routine blood tests.

However, visit your GP if you have the typical signs and symptoms of leukaemia (see above). They will ask you about your symptoms and your medical and family history.

Your GP will also carry out a physical examination to check for swollen glands, a swollen spleen and any signs of abnormal bleeding. You may also be asked to have a blood test.

If your GP suspects leukaemia, they’ll refer you to a haematologist (a doctor who specialises in conditions that affect the blood). You’ll have a full blood count, where the number of different types of blood cell in a sample are counted.

You may also need to have some other tests, such as a chest X-ray, to rule out other possible causes of your symptoms, and an ultrasound scan or a computerised tomography (CT) scan to check your organs.

Read more about how chronic lymphocytic leukaemia is diagnosed.

Treating chronic lymphocytic leukaemia

As most people diagnosed with chronic lymphocytic leukaemia don’t have symptoms, immediate treatment isn’t usually recommended.

Some people can live for years or decades with chronic lymphocytic leukaemia without developing symptoms or needing treatment.

This is because most treatment programmes involve chemotherapy, which has associated side effects. In such cases, a policy of  “watchful waiting” is usually recommended, which involves regular visits to your doctor and blood tests so that your condition can be closely monitored.

If treatment is required, chemotherapy will usually be recommended. Radiotherapy may also be needed to shrink swollen lymph nodes.

Treatment can’t cure chronic lymphocytic leukaemia completely, but it can slow its progression and lead to remission (periods where there are no signs or symptoms).

Read more about treating chronic lymphocytic leukaemia.

Complications of chronic lymphocytic leukaemia

One of the main complications of chronic lymphocytic leukaemia is increased vulnerability to infection.

This is because your immune system will be weakened due to a reduced number of healthy, infection-fighting white blood cells. Having chemotherapy treatment will also weaken your immune system.

Due to the risk of infection, you should have a flu vaccination and a pneumococcal vaccination. Regular doses of antibiotics may also be recommended.

Around 10% of people with chronic lymphocytic leukaemia will develop anaemia due to the breakdown of red blood cells. This form of anaemia is called autoimmune haemolytic anaemia and can be severe, causing fatigue and breathlessness. Steroids are often used to treat autoimmune haemolysis.

Read more about the complications of chronic lymphocytic leukaemia.

Living with chronic lymphocytic leukaemia

Being diagnosed with chronic lymphocytic leukaemia can be difficult to come to terms with. It can affect you both physically and emotionally.

In the early stages, you may not have any symptoms and your quality of life may be unaffected.

If the condition is more advanced, or if you need treatment, you may lack energy and feel very tired all the time, particularly after treatment.

Your treatment programme may also cause side effects. For example, some types of chemotherapy may make your skin more sensitive to light, which means you’ll need to take extra care in the sun.

If you’re diagnosed with cancer, you may experience a range of emotions. You may feel shocked, angry, confused, upset or frightened.

There’s no right or wrong way to deal with a cancer diagnosis, but it’s very important to talk about how you’re feeling with a loved one or a healthcare professional, such as your specialist or a trained counsellor.

Read more about the psychological effects of being diagnosed with chronic lymphocytic leukaemia.

The Cancer UK website also has some useful information and advice about coping with chronic lymphocytic leukaemia and emotions and cancer.

Treatment for chronic lymphocytic leukaemia will depend on what stage the condition is at when it’s diagnosed.

Other factors will also be considered, such as your age and overall level of health and fitness.

Staging

Doctors use stages to describe how far leukaemia has developed. In the UK, the Binet staging system is used for chronic lymphocytic leukaemia. It has three stages:

• Stage A – where you have fewer than three areas of enlarged lymph nodes and a high white blood cell count
• Stage B – where you have more than three areas of enlarged lymph nodes and a high white blood cell count
• Stage C – where you have enlarged lymph nodes or spleen, a high white blood cell count and a low red blood cell or platelet count

An area of lymph nodes refers to lymph nodes in one area of your body, such as in your neck, under you arms or in your groin.

If the lymph nodes on both sides of your body are swollen – under both arms, for example – this counts as one area.

Treating early stage chronic lymphocytic leukaemia

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

The condition often develops very slowly, and if you don’t have any symptoms there is no advantage in starting treatment early.

In such cases, a policy of “watchful waiting” is usually recommended, which involves regular visits to your doctor and blood tests, so that the condition’s progress can be carefully monitored.

Treatment for chronic lymphocytic leukaemia will usually only be recommended if you have:

• symptoms, such as severe tiredness and weight loss 
• enlarged lymph nodes
• bone marrow failure 
• rapidly rising numbers of lymphocytes (white blood cells) in your bloodstream

Chemotherapy (see below) is usually the first treatment that’s recommended. Radiotherapy can also be used to shrink enlarged lymph nodes, and surgery can be used to remove a swollen spleen.

Treating symptomatic chronic lymphocytic leukaemia

As chronic lymphocytic leukaemia often develops very slowly, the timescales for treatment vary considerably.

Some people don’t experience symptoms for a long time and may not need treatment for many years, possibly decades.

For others, particularly those with certain genetic abnormalities, the condition may progress much faster (within a few months).

If you have later-stage chronic lymphocytic leukaemia (stage B or C), your haematologist (blood specialist) will probably recommend chemotherapy.

Chemotherapy

The standard treatment programme for chronic lymphocytic leukaemia is a combination of three medications: fludarabine, cyclophosphamide and rituximab (FCR).

Fludarabine and cyclophosphamide are usually given in tablet form and taken for five days every 28 days. Rituximab is given intravenously (directly into a vein) over the course of several hours.

You can read the NICE guidance about fludarabine for treating chronic lymphocytic leukaemia.

Most people benefit from FCR. Although it won’t cure the condition, it usually leads to remission – where there’s no sign of leukaemia and you don’t have any symptoms. It can last for many months or several years.

After a period of remission, the leukaemia can return and you may begin to experience symptoms again. This is known as a relapse. If chronic lymphocytic leukaemia returns, you may need to have more chemotherapy and biological therapy.

Chemotherapy can weaken your immune system, which is known as being immunocompromised. This can be serious, as it can cause infections to develop.

You may be prescribed a course of antibiotics to take during your chemotherapy treatment to help prevent infections.

Read more about the complications of chronic lymphocytic leukaemia.

Rituximab

Rituximab is a monoclonal antibody, which are genetically engineered in a laboratory.

Rituximab works by sticking to a protein found on the surface of  the lymphocytes (cancerous white blood cells). The immune system then targets and destroys the lymphocytes.

Rituximab is commonly used in combination with other chemotherapy medication, such as fludarabine and cyclophosphamide (see above).

It’s given intravenously (directly into a vein) over the course of several hours. This is known as an infusion.

Common side effects of rituximab include flu-like symptoms, such as feeling sick, headache, a high temperature and chills. You may also have an itchy rash in the area where the medication enters the vein.

Most side effects of rituximab occur within 24 hours of treatment starting for the first time. You will be closely monitored once your treatment begins.

If you start to experience an adverse reaction, such as shortness of breath or chest pain, anti-allergy medicines, such as corticosteroids, can be used to help relieve your symptoms.

Other chemotherapy options

Alemtuzumab

Alemtuzumab is like rituximab – a medication called a monoclonal antibody that recognises certain proteins on the surface of lymphocytes, attaches to them and helps destroy them. Alemtuzumab and rituximab recognise different surface proteins.

Alemtuzumab may be considered if your leukaemia has stopped responding to chemotherapy, or has returned following chemotherapy treatment.

Like rituximab, alemtuzumab is administered intravenously. It can also be given by injection.

The main side effect of alemtuzumab is that it can weaken your immune system and make you vulnerable to infection. You will therefore be prescribed antibiotics while taking it.

Bendamustine

Bendamustine is a fairly new medication for treating chronic lymphocytic leukaemia.

The National Institute for Health and Care Excellence (NICE) recommends bendamustine as a treatment option for people with advanced chronic lymphocytic leukaemia (stage B or C) who are unable to tolerate fludarabine.

Bendamustine is given by infusion, twice a week every four weeks. This cycle of treatment may be repeated up to six times. The most serious side effect of bendamustine is a weakened immune system. It may be given in combination with rituximab.

You can read the NICE guidance about bendamustine for treating chronic lymphocytic leukaemia.

Chlorambucil

Chlorambucil is a chemotherapy medication that is given in tablet form usually for seven days, once a month for six months.

It’s sometimes given in combination with rituximab. It can have side effects, such as low blood counts and infections, but is generally well tolerated. It’s sometimes used in people who aren’t fit enough to receive FCR or bendamustine.

Ofatumumab

Ofatumumab is a monoclonal antibody that is similar to rituximab. It’s sometimes used in people with chronic lymphocytic leukaemia that’s relapsed after receiving fludarabine and alemtuzumab, or in those who aren’t fit enough to receive these medications.

It’s given as an infusion, and the main side effects are allergic reactions and low blood counts.

Bone marrow and stem cell transplants

Bone marrow or stem cell transplants are sometimes used to treat chronic lymphocytic leukaemia.

This type of intensive treatment aims to get rid of chronic lymphocytic leukaemia completely, or control it for longer periods.

Before having a bone marrow or stem cell transplant, you will have a number of tests to check you’re fit enough to have this type of intensive treatment.

You’ll also be given aggressive, high-dose chemotherapy and radiotherapy to destroy any cancerous cells in your body and put the leukaemia into remission. This can place significant strain on your body and can cause additional side effects.

Bone marrow and stem cell transplants have better outcomes when the donor has the same tissue type as the person receiving the donation. Therefore, the best donor is usually a brother or sister with the same tissue type.

Due to these issues, transplants are usually only successful when they’re carried out in children and young people, or older people in good health, and there’s a brother or sister who’s able to provide a donation.

In many cases of chronic lymphocytic leukaemia, the potential risks of transplantation far outweigh any benefit. For example, the chances of an elderly person with advanced chronic leukaemia surviving a bone marrow transplant can be as low as one in five.

Read more about bone marrow transplants.

Deciding against treatment

As many of the treatments described in this section have unpleasant side effects that can 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 making a decision about your treatment, and before making a decision you can talk to your doctor, partner, family and friends.

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