Acute lymphoblastic leukaemia (ALL)

Acute lymphoblastic leukaemia (ALL) is a fast-growing type of blood cancer that affects a type of white blood cell called a lymphoid blast.

ALL usually starts because of random changes in the lymphoid blasts, which happen just by chance.

Normally, lymphoid blasts are made in the bone marrow and then mature and develop into lymphocytes. A lymphocyte is a type of white blood cell which is really important for helping our bodies fight infection. Usually, our bone marrow makes the right number of lymphocytes to keep our immune system working normally.

If you have ALL, this process goes wrong. Instead of growing into lymphocytes, some of the lymphoid blasts begin to multiply in an uncontrolled way. These are known as leukaemia cells. As more and more of these leukaemia cells are made, they start to crowd out the normal, healthy blood cells in your bone marrow.

When healthy blood cells are crowded out, it makes it hard for your body to do the things it normally does to keep you healthy, like fight infection.

These leukaemia cells can then start to spill into your bloodstream and into other areas of your body.

Some of the most common symptoms of ALL include:

• Unexplained tiredness (fatigue)
• Bruising and bleeding
• Getting lots of infections
• Weight loss
• Pain in the bones or joints
• Lumps in your neck, armpits or groin where your lymph nodes have swollen.

We have more information about symptoms of B-cell acute lymphoblastic leukaemia and T-cell acute lymphoblastic leukaemia.