Acute Myeloid Leukaemia (AML) is a form of cancer that develops in your bone marrow and affects your blood cells. This is because all blood cells are made in the bone marrow, the soft material inside your bones, having developed from ‘parent’ bone marrow stem cells. AML arises in myeloid stem cells which would normally go on to make certain types of white blood cells, as well as red blood cells and platelets. Because of their abnormal nature, AML cells do not develop fully and remain ‘immature’. These cells have a distinctive appearance that can be recognised by specialists when diagnosing AML.

Every day our body makes around ten billion new blood cells and the control of how these cells develop is coded within our DNA. The DNA code is normally copied very precisely, but mistakes can very rarely occur due to chance. In order to develop AML, several mistakes must occur in key genes that control blood cell production.

For a more detailed explanation of blood cell production, the bone marrow and the immune system please visit

AML is most common in people over 60 years of age but it can affect any age including children. The higher rate in older adults is due to the fact that more time has passed in which to acquire errors in the DNA code which can cause AML.

There is no absolute cause for AML but there are factors that can increase the risk of it developing including:

  • Exposure to radiation or industrial chemicals such as benzene
  • Pre-existing related blood conditions: Myelodysplasia or Myeloproliferative Neoplasms
  • Previous treatment for cancer with chemotherapy and/or radiotherapy
  • Family history of AML

When you develop AML, there is a marked decrease in normal blood cell production which leads to symptoms in keeping with the type of cells that are reduced. These may include:

Red Blood Cells. These contain haemoglobin, the protein that carries oxygen around the body, and their decrease can cause:

  • Fatigue - tiredness that is unusual and that does not improve with rest/sleep
  • Breathlessness - becoming short of breath when undertaking standard activities of daily living (like climbing the stairs)
  • Dizziness - when standing up from a seated position or when standing for long periods
  • Headaches - when expending energy

Platelets. These are involved in helping the blood to clot and their reduction may result in:

  • Bruising - more than normal without any significant trauma
  • Bleeding - this can be from your gums after brushing, from your nose and for women their menstrual period can be heavier than they are used to
  • Petechiae - small red or purple spots on the skin, which are caused by bleeding from broken capillary blood vessels
  • Bleeding from the bowel - black, tarry stools

White Blood Cells. These are normally involved in fighting infection and their decrease may lead to:

  • Infection – recurrent or severe infections such as urinary tract infections, pneumonia, cellulitis (skin infections) or gastroenteritis
  • High fever
  • Excessive sweating – in the night or day

In some people who have very high levels of AML cells in the blood (these are called abnormal white blood cells or ‘blasts’) the blood may become more ‘sticky’ and flow slowly. This may cause:

  • Breathlessness (due to abnormal cells in the lungs)
  • Blurred vision
  • Headaches
  • Fatigue

Acute promyelocytic leukaemia (APL) is a subtype of acute myeloid leukaemia (AML). It is a form of cancer that affects blood-producing cells in the bone marrow (called promyelocytes). It happens when these cells don’t mature properly and become cancerous.