What is blood cancer?

Blood cancers happen when the blood cells do not develop properly.

The most common blood cancers are:

But there are also other blood cancers called:

  • myeloproliferative neoplasms (MPN).

To understand blood cancers, it can help to know more about your blood and blood cells.

Different types of blood cancer affect different types of cells in the blood. We explain more about the types below.


Leukaemia is a cancer of the white blood cells. People with leukaemia have too many abnormal white blood cells in their bone marrow. This usually means their white blood cell count is high. But in a few people with leukaemia, their white blood cell count is low.

The abnormal white blood cells are called leukaemia cells. They behave differently from healthy white blood cells.

The type of leukaemia is named based on the type of white blood cell that has become abnormal. Leukaemia can either grow quickly (acute) or more slowly (chronic).

There are four main types of leukaemia:


Lymphoma is a cancer of a type of white blood cell called lymphocytes. The abnormal lymphocytes or lymphoma cells may build up and form a lump or tumour. The most common place for this to happen is in a group, or more than one group, of lymph nodes. But lymphoma can also happen in other organs in the body.

There are two main types of lymphoma:


Myeloma is a cancer of plasma cells. Plasma cells are a type of white blood cell. They are part of the immune system and help protect the body against infection. They make proteins called antibodies, which help fight viruses or bacteria in the body.

Myelodysplasia (MDS)

Myelodysplasia is a type of blood cancer where the bone marrow makes some unhealthy blood cells. This means there are not enough healthy blood cells in the blood. MDS can affect red blood cells, white blood cells and platelets. Myelodysplasia is also known as myelodysplastic syndrome (MDS).

Sometimes, over time, MDS can develop into acute myeloid leukaemia (AML).

MPN (myeloproliferative neoplasms)

Myeloproliferative neoplasms (MPNs) are also blood cancers.

They happen when the bone marrow makes too many of one type, or more than one type, of blood cell. These cells all start from myeloid stem cells.

A diagnosis of any cancer can be frightening. But most MPNs develop very slowly. Rarely, MPNs develop into an acute leukaemia.

The main types of MPN are:

Essential thrombocythaemia (ET)

The body makes too many blood clotting cells, called platelets. People with essential thrombocythaemia (ET) have a higher risk of getting a blood clot (thrombosis). Some people with ET develop myelofibrosis.

Polycythaemia vera (PV)

The body makes too many red blood cells. This can make the blood thicker than normal. People with polycythaemia vera (PV) have a higher risk of getting a blood clot (thrombosis). Some people with PV develop myelofibrosis.

Myelofibrosis (MF)

In people with myelofibrosis, the bone marrow becomes scarred. This means it cannot make blood cells properly.

Reviewed: 08 November 2019
Reviewed: 08/11/2019
Next review: 08 May 2022
Next review: 08/05/2022

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