Leukaemia in children

Key facts Leukaemia is a type of cancer that affects the blood. There are many types of leukaemia. Most childhood leukaemias are acute — they appear fast and grow quickly. If you are worried that your child has symptoms of leukaemia, talk to your child’s doctor. What is leukaemia? Leukaemia is a type of cancer that affects the blood. It starts in the bone marrow, where blood cells are made, and spreads to the bloodstream. Leukaemia happens when the bone marrow makes too many white blood cells (lymphocytes). Lymphocytes are a part of the immune system and help to fight infection. Types