Acute lymphoblastic leukaemia

Also called ALL or Acute lymphoblastic leukemia

Acute lymphoblastic leukaemia is a cancer in which the bone marrow makes large numbers of immature white blood cells called lymphoblasts. They crowd out healthy blood cells, which causes infections, tiredness and bleeding. It develops quickly and is treated straight away, in specialist centres.

Last updated Nov 9, 2026

What it is

It is the most common cancer in children, and most children are cured. It can also affect adults, in whom treatment is often more demanding.

Treatment is usually chemotherapy given in phases over two to three years, and sometimes targeted medicines, immunotherapy or a stem cell transplant.

Common signs

  • Pale skin, tiredness and breathlessness
  • Frequent or severe infections
  • Bruising and bleeding easily, including nosebleeds
  • Bone or joint pain, swollen lymph nodes, fever

How it is usually diagnosed

  • A full blood count and blood film
  • A bone marrow biopsy, with genetic and other specialist tests on the cells
  • Sometimes a lumbar puncture and scans

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Blood counts throughout treatment
  • Bone marrow and genetic test reports
  • Your treatment protocol and the dates of each phase
  • Discharge letters and transfusion records
  • Long-term follow-up plan after treatment ends

Questions to ask your doctor

  • Which type of ALL is it, and what does that mean for treatment?
  • What does each phase involve, and how long will it last?
  • Which signs of infection mean I must call the team straight away?
  • What long-term follow-up will be needed?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • A temperature of 38°C or more during treatment (call your treatment team immediately)
  • Bleeding that will not stop
  • Breathlessness, confusion or feeling suddenly very unwell

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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