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
The 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 can also collect in the , causing them to swell.
It is common for people with CML to feel very tired. This is because your isn't able to make enough . 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.
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.
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.
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.
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.
Low levels of 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).
Some people gradually lose their appetite. This can be due to the swollen spleen pressing on the stomach.
These symptoms may occur but are usually in the later stages of CML.
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.
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.
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.
Last reviewed: 03 Jun 2025
Next review due: 03 Jun 2028
You usually start by seeing your GP if you have symptoms. Find out what happens when you see your GP and how to get the most out of your appointment.
Many people with chronic myeloid leukaemia won't have any symptoms. Your GP should refer you to have a blood test or see a blood specialist if they think you might have CML.
Your doctor may suspect or sometimes diagnose CML from a blood test. You then have more tests to confirm your diagnosis and find out more about your CML.
Your doctors does tests on your blood and bone marrow to look for changes in certain genes. Find out about the different types they do.
Chronic myeloid leukaemia (CML) is a type of cancer that affects the blood and bone marrow. It usually develops very slowly.
CML starts in the white blood cells called granulocytes. It often develops slowly and treatment can keep it under control for many years. Find out more.
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