Blood cancer

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:

• acute myeloid leukaemia (AML)

• acute lymphoblastic leukaemia (ALL)

• chronic myeloid leukaemia (CML)

• chronic lymphocytic leukaemia (CLL)

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.

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:

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.

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