Acute myeloid leukaemia (AML) Getting an AML diagnosis can feel overwhelming because everything happens so fast. It's an aggressive type of blood cancer and you'll probably be advised to start treatment right away. It's also a complex condition, so it helps to have clear information. 'Acute' means AML develops rapidly, and 'myeloid' tells you that it affects a particular group of white blood cells. AML occurs when abnormal cells in your bone marrow grow uncontrollably and don't develop properly into mature blood cells. These immature cells are called myeloid blasts. AML affects your white blood cells, and sometimes your red blood cells and platelets. In our general information about leukaemia, you can learn more about blood cells and the way they are made in a process called haematopoiesis. What are the symptoms of AML? The symptoms of AML appear over a few days or weeks and are likely to get worse quickly. These symptoms can include: tiredness feeling weak pale skin breathlessness unusual bleeding or bruises frequent infections losing weight fever sweating full or tender feeling in your abdomen swollen glands in your neck, armpits, or groin. What causes AML? We don't know what causes AML. The chances of developing AML are higher than usual for people who: Smoke Are overweight Have been exposed to the chemical benzene Had previous chemotherapy or radiotherapy Have certain inherited conditions, including Down's syndrome Have certain autoimmune or blood disorders Have been exposed to high levels of radiation (but hardly anyone is exposed to these levels in everyday life) In the UK, about four in 10 people with AML are aged 75 or older. It affects more men than women. It's rare, but AML can affect children. This is a very difficult situation for your child, you, and the whole family, but it may be comforting to know that treatment is most likely to succeed in this age group. How is AML diagnosed? If AML is suspected, you'll be offered blood tests and a bone marrow biopsy to confirm the diagnosis. In the laboratory, the cancer cells can be analysed for abnormal genes, to determine what type of AML you have. This information is important because it helps your doctor choose the best treatment to recommend. Sometimes, AML can spread to other parts of the body, so your doctor may recommend a lumbar puncture to check your spinal fluid for cancer cells. You may also have other tests such as a chest X-ray or heart scan. What are the types of AML? AML is divided into different sub-types. There are two systems used to classify AML, called the French-American-British (FAB) system and the World Health Organization (WHO) system. Some people have a specific sub-type of AML called acute promyelocytic leukaemia (APL or APML), which is treated differently from the other types of AML.