When to worry about unexplained weight loss with leukaemia

Leukaemia may cause reduced appetite, fatigue, fever, sweating, nausea, or changes in the body’s energy use. Treatment can also affect taste, digestion, appetite, and the ability to prepare or finish meals. Weight change may have more than one cause, including infection, medicines, mouth soreness, or emotional strain, so it needs an individual review.

Note the timing of the change and any fever, night sweating, pain, mouth ulcers, nausea, diarrhoea, constipation, or reduced appetite. Tell your team if tiredness makes shopping, cooking, or eating difficult.

Tell your haematology team about weight loss rather than waiting for the next routine appointment. Share your food and fluid intake, symptoms, and medicines. The team can check for treatment effects, infection, dehydration, mouth problems, and nutritional concerns, and can involve a dietitian when useful.

Try manageable meals and regular sips of fluid if these are tolerated. Avoid unapproved supplements or raw-food changes without advice, particularly when treatment affects infection protection or interacts with medicines.

During leukaemia treatment, contact your team urgently for fever or chills, sudden breathlessness, confusion, fainting, uncontrolled bleeding, repeated vomiting, or inability to drink. Seek immediate help for severe weakness or signs of dehydration, including very little urine. Follow the emergency contact instructions given by your treatment centre.

Ask whether the change could relate to treatment, infection, medicines, or mouth and digestive symptoms; how to maintain nutrition safely; and which symptoms should trigger a same-day call.