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.