Acute myeloid leukaemia (AML)

What is acute myeloid leukaemia (AML)?

Acute myeloid leukaemia (AML) is a type of blood cancer that affects the blood and bone marrow. It starts from the fast, uncontrolled growth of early white blood cells called myeloid stem cells.

How does the body make blood cells?

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

Your body makes in the bone marrow. The bone marrow is the soft, spongy tissue in the inner part of your bones. You make blood cells in a controlled way, as your body needs them. This continuous supply keeps your blood healthy and your body functioning properly.

All blood cells start as the same type of cell, called a stem cell. This stem cell can turn into any type of blood cell. The stem cell can develop into:

  • myeloid stem cells

  • lymphoid stem cells

Myeloid stem cells become:

  • monocytes

  • red blood cells

  • platelets

  • white blood cells called granulocytes - neutrophils are a type of granulocyte

Lymphoid stem cells develop into white blood cells called lymphocytes. Examples include B lymphocytes and T lymphocytes.

The diagram below helps to explain this:

A simplified diagram showing how blood cells are made.

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.

Diagram showing the cells in which AML starts.

What happens in AML?

These abnormal cells build up in the bone marrow. They block healthy blood cells from developing. They can also spill out into the blood and eventually spread to other parts of the body. This includes the:

  • liver 

  • ​

  • gums, skin, muscle, and ​, but this is less common

The word acute means that the leukaemia can develop fairly quickly. This is different from chronic leukaemia which usually develops very slowly.

Find out about other types of leukaemia

You usually need to start treatment quickly after your diagnosis. If you don't have treatment, the leukaemia will cause death within a few weeks or months. But improvements in treatment mean doctors can now plan treatment based on your situation and health.

Your outlook () for AML depends on many factors including:

  • age at diagnosis

  • in the leukaemia cells

  • how advanced the AML is

Find out more about survival for AML

How does leukaemia affect the body?

Leukaemia can affect your blood and other areas of your body.

White blood cells

White blood cells help fight infection. If your body makes a lot of abnormal white blood cells, they can prevent normal healthy cells from developing. So you are more likely to get infections and may find it difficult to get rid of them.

Red blood cells and platelets

Too many white blood cells can overcrowd the bone marrow. So there isn't enough space to make other types of blood cells. This can cause a lower than normal number of red blood cells and platelets.

Having too few red blood cells is called anaemia. It can make you tired and breathless.

Platelets are blood cells that help your blood to clot. If you don’t have enough platelets, you can have bleeding problems such as bruising or nosebleeds.

Other parts of your body

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

The leukaemia cells can also spread to the brain in some people.

Find out about symptoms of AML

How common is AML?

AML is rare. Around 2,700 people are diagnosed with AML in the UK every year. This number includes children and adults.

Who can get AML?

Adults or children can get AML. It is most common in older people. Around 40 out of 100 (around 40%) of new cases are in people aged 75 and over.

Find out about risks and causes of AML

Last reviewed: 25 Sept 2023

Next review due: 25 Sept 2026

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