The blood and acute myeloid leukaemia

Leukaemia is a cancer of the white blood cells and bone marrow. Because white blood cells are found in the lymph nodes and the spleen, leukaemia can affect them, as well as other organs in the body.

Leukaemia is a complicated disease. There are several types and subtypes. The name of the leukaemia you have depends on

• How quickly it develops
• The type of white blood cell that becomes cancerous

In acute myeloid leukaemia (AML) white blood cells called granulocytes or monocytes become cancerous. AML usually develops quickly, over days or weeks. It is the most common type of leukaemia in adults. It is most often diagnosed in older people, and is most common in people over 65 years old.

To understand how and why leukaemia affects you as it does, it helps to know about blood cells.

Your body makes blood cells in the bone marrow. The bone marrow is the soft inner part of your bones. You make blood cells in a controlled way, as your body needs them.

All blood cells start as the same type of cell, called a stem cell. This stem cell then develops into

• Myeloid stem cells, which become white blood cells called monocytes and granulocytes (neutrophils)
• Lymphoid stem cells, which become white blood cells called lymphocytes
• Erythroblasts, which become red blood cells
• Megakaryoblasts, which become platelets

The diagram below helps to explain this.

There is information about blood cells and what they do in the section about your body.

Doctors divide leukaemia into two main groups based on the speed that the leukaemia develops. Acute leukaemia develops very quickly. Chronic leukaemia tends to develop slowly, usually over months or years. For a long time, it may not cause many symptoms.

Doctors further divide these groups depending on the type of white blood cell they affect. Acute leukaemias include

• Acute myeloid leukaemia (AML), which affects myeloid cells
• Acute lymphoblastic leukaemia (ALL), which affects lymphoid cells

Chronic leukaemias include

• Chronic myeloid leukaemia (CML), which affects myeloid cells
• Chronic lymphocytic leukaemia (CLL), which affects lymphocytes

This section is about acute myeloid leukaemia (AML). There are sections about the other types of leukaemia elsewhere on the site. The links above take you to information about the other types. Or you can look for them on our list of specific cancers.

In acute myeloid leukaemia, the bone marrow makes too many monocytes or granulocytes. These cells are not fully developed and are not able to work normally.

White blood cells help fight infection. But leukaemia makes your body make abnormal white blood cells that don’t work properly. So you are more likely to get infections and find it difficult to get rid of them.

If there are too many white blood cells, the bone marrow gets overcrowded and there is not enough space for other types of blood cells. So you may have lower than normal levels of red blood cells and platelets.

Having too few red blood cells makes you tired and breathless (anaemic). If you don’t have enough platelets, you can have bleeding problems, such as bruising or nosebleeds.

Abnormal white blood cells can also build up in parts of the lymphatic system (the spleen and lymph nodes), and in the liver. This can make your tummy (abdomen) swell and feel uncomfortable.

There is detailed information about the symptoms of acute myeloid leukaemia in this section.