Symptoms of chronic myeloid leukaemia (CML)

Many people with chronic myeloid leukaemia (CML) won't have any symptoms at all. They are diagnosed because they have a routine blood test for something else.

The symptoms of CML can be similar to those caused by other illnesses. The symptoms tend to be mild at first and get worse slowly. If you do have symptoms, they can include:

  • feeling full or pain in your tummy (abdomen)

  • swelling of your lymph nodes

  • feeling weak or tired

  • weight loss

  • heavy sweating at night

  • a high temperature (fever)

  • pain in your bones or joints

  • picking up infections more often than usual

  • bruising and bleeding easily

  • loss of appetite

See your GP if you have any of these symptoms. Or you have symptoms that are unusual for you or won't go away. Your symptoms are unlikely to be cancer, but it is important to get them checked by a doctor.

Tummy discomfort or swollen lymph nodes

The spleen Open a glossary item is an organ on the left side of your tummy (abdomen), just under your ribs. It can become swollen and larger than normal. This can cause discomfort or pain in your abdomen. It might also make you feel full. Your doctor may be able to feel your enlarged spleen.

In CML, abnormal white blood cells Open a glossary item can also collect in the lymph nodes Open a glossary item, causing them to swell.

Diagram showing the position of the spleen

Tiredness and looking pale

It is common for people with CML to feel very tired. This is because your bone marrow Open a glossary item isn't able to make enough red blood cells Open a glossary item. They are crowded out by the large numbers of abnormal white blood cells. A shortage of red blood cells is called anaemia. This can make you feel breathless and tired.

Weight loss

CML can use up energy that your body would otherwise use or store. So you may lose weight, even if you think you are eating normally.

You might feel full more quickly than usual if you have a swollen spleen and it is squashing your stomach. This may make you eat less and lose weight.

High temperature or sweating

Some people may have a sudden high temperature (fever). Or they may sweat more than usual. This can occur more often at night and some people find they need to change their bedsheets.

Bone or joint pain

Sometimes you may get aches in your bones. This is because there are leukaemia cells building up in the bone marrow, increasing pressure on nerves and causing pain.

Some people get stiff joints. They may get swollen due to a build up of body salts in the tissues. This can also be painful.

Infections that will not get better

As the number of abnormal white blood cells rise, you may pick up infections more easily. This is because the abnormal white blood cells cannot fight off infection as well as healthy ones.

Abnormal bruising or bleeding

Low levels of platelets Open a glossary item in the blood can cause bleeding or bruising. You may find that you bruise more easily than usual or with no obvious cause. You may also have bleeding from the gums or nose. More rarely people notice a fine rash of dark red spots (called purpura). 

Poor appetite

Some people gradually lose their appetite. This can be due to the swollen spleen pressing on the stomach.

Less common symptoms

These symptoms may occur but are usually in the later stages of CML.

Headaches

If you have a very high white blood cell count, the extra cells can clog the smallest blood vessels in the brain. This can cause headaches in some people.

Eyesight changes

If you have a very high white blood cell count, the extra cells can clog the smallest blood vessels in the eyes. This may cause eye problems such as blurred vision.

Persistent painful erections

Doctors call this priapism. It is a rare symptom. Priapism is an erection that won't go down and can become very painful. It is caused by the abnormally high number of white blood cells in the blood blocking up tiny blood vessels in the penis.

A priapism is an emergency. If you have persistent painful erection then you need medical attention. An erection that lasts too long can cause permanent damage to the penis.

When to see your doctor

If you have any of these symptoms you must have them checked by your GP.

The symptoms of CML are often vague and can be caused by other medical conditions.

Most people with these symptoms will not have chronic myeloid leukaemia.

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    VT DeVita, TS Lawrence, SA Rosenberg
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  • Chronic myeloid leukaemia
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  • BMJ Best Practice Chronic myeloid leukaemia
    M J Mauro, R Connor and R E Clark
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  • A British Society for Haematology Guideline on the diagnosis and management of chronic myeloid leukaemia
    G Smith and others
    British Journal of Haematology, October 2020. Volume 191, Issue 2, Pages 171 - 193

  • Chronic myeloid leukemia: 2025 update on diagnosis, therapy, and monitoring
    E Jabbour and H Kantarjian
    American Journal of Hematology, November 2024. Volume 99 Issue 11, Pages 2191 - 2212

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk if you would like to see the full list of references we used for this information.

Last reviewed: 
03 Jun 2025
Next review due: 
03 Jun 2028

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