Leukaemia begins in the bone marrow and affects lymphocytes and granulocytes, two types of white blood cells.

Leukaemia is the most common form of childhood cancer - one in three children with cancer have Leukaemia. However, more adults than children are diagnosed with Leukaemia. Leukaemia represents just over 5% of all cancers.

It is a cancer of the blood and bone marrow. It is characterised by the uncontrolled accumulation of blood cells. Types of leukaemia are grouped by the type of cell affected and by the rate of cell growth. Leukaemia is either acute or chronic.

When people speak of "Leukaemia" there are a variety of specific conditions that include leukaemia, aplastic anaemia, lymphoma, myeloma and related blood diseases.

Leukaemia, a Greek word meaning white blood, was identified in 1845. The first drugs that were effective for the treatment of Leukaemia did not appear until the 1950's. Thirty years ago, patients diagnosed with Leukaemia faced a poor prognosis. Thanks to developments in medical research and new treatments, around eight in every 10 children, and three in every 10 adults survive acute leukaemia after treatment.

In the US the spelling is different leukemia.

"When you are looking for information about Leukaemia, it really helps to know the proper medical diagnosis so that you can find the correct information."
Androulla - Leukaemia Cancer Society

The four most common types of leukaemia are:

  • Acute lymphocytic leukaemia
  • Acute myeloid leukaemia
  • Chronic lymphocytic leukaemia
  • Chronic myeloid leukaemia

The type of the leukaemia you have will affect how quickly it develops and the kind of white blood cells it affects. Chronic leukaemia is a slow-growing leukaemia. Acute leukaemia is a fast-growing leukaemia that develops quickly without treatment.

Acute lymphocytic leukaemia

Acute lymphoblastic leukaemia (ALL) affects white blood cells. ALL develops quickly, replacing healthy cells with leukaemia cells that can't mature properly. ALL requires immediate treatment.

Although ALL can affect both children and adults, most cases of acute lymphoblastic leukaemia develop in children, teenagers and young adults. About 790 people are diagnosed with ALL each year in the UK.

Acute myeloid leukaemia

Acute myeloid leukaemia is an aggressive cancer of the myeloid cells, with around 3,100 people diagnosed with it each year in the UK. The risk of developing AML increases with age. Like ALL, AML causes the bone marrow to overproduce abnormal white blood cells, crowding healthy blood cells and affecting the body’s ability to fight infections.

Chronic lymphocytic leukaemia

About 25% of all leukaemia cases are CLL. About one in every 175 people may develop CLL in their lifetime.

CLL is like ALL, but it’s chronic instead of acute, meaning that it’s more slow-growing and takes longer to start causing symptoms.

Chronic myeloid leukaemia

CML, also known as chronic myelogenous leukaemia, is slow-growing, but once it starts causing symptoms, these may include fatigue, fever, weight loss and an enlarged spleen. Around half of CML cases are diagnosed by a blood test before symptoms have begun.

Risk factors

No one knows exactly what causes leukaemia. People who have it have certain unusual chromosomes, but they don’t cause leukaemia. The risk factors include

  • Smoking
  • Exposure to a lot of radiation or certain chemicals
  • Had radiation therapy or chemotherapy to treat cancer
  • Family history of leukaemia
  • A genetic disorder like Down syndrome


Symptoms can vary depending on the type of leukaemia but here are some of the more common symptoms of leukaemia are:

tiredness that lasts a long time and doesn’t improve with rest bruising and bleeding more easily repeated infections and high temperatures unexplained weight loss swollen lymph nodes - the glands in your neck, armpit and groin

Leukaemia symptoms are often vague and not specific. You may overlook early symptoms because they may resemble symptoms of the flu and other common illnesses.


Some types of leukaemia are slow growing and do not need to be treated straight away or ever. This is called 'watch and wait'. It can be confusing and upsetting for patients as we all have a sense of urgency about cancer diagnosis and treatment. For some patients, 'watch and wait' is the best approach.

Chemotherapy uses drugs to kill cancer cells or stop them from growing.

Other drug therapies or targeted therapies. These are other drug therapies that can be used on their own or with chemotherapy.

Stem cell transplant, blood stem cells, cells at their earliest stage of development, are transplanted from a healthy person who matches your tissue type.

© 2022 Leukaemia Cancer Society