Leukaemia is a type of cancer that affects the formation of white blood cells in your body. It affects the blood and bone marrow, where blood cells are made. Leukaemia may be acute, appearing fast and growing quickly, or chronic, appearing gradually and growing slowly.
While the cause of leukaemia is not known in most cases, there are treatments available that can help manage the disease. Acute leukaemia can be cured. There is no cure for chronic leukaemia, but it can often be managed by lifelong treatments.
How leukaemia affects the body
If you have leukaemia, your bone marrow makes large numbers of abnormal white blood cells. These abnormal cells build up in the bone marrow and then spill out into the blood and crowd out the healthy cells. They may then spread to organs such as the liver, spleen, lungs and kidneys, and in some cases, the brain and spinal cord.
When your body doesn’t have enough healthy blood cells, this can lead to a range of problems. For example, a lack of red blood cells can cause weakness, tiredness and breathlessness. A lack of healthy white blood cells lowers your immunity to disease and infections. A lack of platelets can make it easy to bruise and bleed.
Types of leukaemia
There are four main types of leukaemia. These are named according to the type of cells affected (‘lymphoid’ if from the lymphatic system, or ‘myeloid’ if from the bone marrow), and how quickly the cancer cells grow (‘acute’ if fast; ‘chronic’ if slow).
- Acute lymphoblastic leukaemia (ALL), also called acute lymphocytic leukaemia – the most common type of leukaemia in children, and can also affect adults.
- Acute myeloid leukaemia (AML), sometimes called acute myelocytic, myelogenous or granulocytic leukaemia – can occur at any age, although it tends to affect older people.
- Chronic lymphocytic leukaemia (CLL) – the most common type of leukaemia in adults. CLL tends to be slow-growing and may have little impact on a person’s health for months or even years.
Chronic myeloid leukaemia (CML) – tends to progress over weeks or months. CML mostly affects older adults and is rare in children.
Last reviewed: April 2017