About Leukaemia

There are 137 different types of blood cancer and four main types of leukaemia.

What is leukaemia?

Leukaemia is a type of blood cancer. It starts in the blood-forming tissue, usually the bone marrow, and leads to the over-production of abnormal white blood cells, the part of the immune system that defends the body against infection. 

To understand leukaemia, it helps to know more about your blood, which has three main cells groups. They have different jobs: 

  • White blood cells fight off infection
  • Red blood cells carry oxygen around your body, and take carbon dioxide back to your lungs so you can breathe it out
  • Platelets helps your blood clot up, to prevent bleeding

You body is making fresh new blood cells all the time, to replace old ones that have worn out and died off. This happens mainly in your bone marrow. When you're healthy, this system is finely balanced in a process called haematopiesis. 

Here's what is supposed to happen: 

  • The process starts with a stem cell, which is an immature cell that can develop into all types of blood cells.
  • When the stem cell divides, it can either produce more stem cells, or other immature blast cells that develop into mature blood cells over time. 
  • In this process of specialisation, immature blast cells become either lymphoid or myeloid cells. 
  • Lymphoid cells are a type of white blood cells. They help fight infection, and they include B lymphocytes and T lymphocytes.
  • Myeloid cells go on to form red blood cells, platelets and other types of white blood cells such as monocytes and granulocytes. 

This process of specialisation (where generic cells change into specific cells) is important, because you need different types of blood cells to do different tasks in the body. 

Leukaemia develops when this process goes wrong, and the white blood cells develop in an uncontrolled way. Your body is making too many white blood cells and they may not be fully formed or mature.  This means your white blood cells can't do their job of fighting infection. They may also crowd out your red blood cells and platelets, so they can't work properly either. 

Types of leukaemia

There are four different types of leukaemia. Partly, the name depends on whether it is chronic or acute:

  • Chronic leukeamia may take a while to get worse
  • Acute leukaemia gets worse quickly without treatment. The white blood cells are also more abnormal than in chronic leukaemia. 

The leukaemia name also tells you what specific type of white blood cell is affected. 

Who can be affected by leukaemia?

People of any age, gender and ethnicity can develop leukaemia. Whilst the highest incidence of leukaemia is observed in older adults, leukaemia is the most common of all the cancers diagnosed in children. Leukaemia is more prevalent in white and black males than in Asian males and more common in white females compared to Asian or black females. 

Leukaemia tends to occur in elderly people and children. In the UK, the average age at diagnosis of leukaemia is 71 years, but leukaemia is also the most common childhood cancer; it accounts for about 33% of all cases of cancer in those under 14 years of age.

Understanding more about Myeloma

about leukaemia

Myeloma is a relatively rare blood cancer arising from a specific type of white blood cells called plasma cells. Understand more about myeloma cancers.

Understanding more about Lymphoma

about leukaemia

Lymphoma is a blood cancer that begins in the lymphatic system. Find out more about the different types of lymphoma and how it develops.