What should you know about radiation fatigue?

You may feel heavy, sleepy or weak, need more rest, or find ordinary tasks harder to complete. Concentration and motivation can also dip. Fatigue may reflect the body’s response to treatment, inflammation, disrupted sleep, reduced activity, pain or emotional strain. Anaemia, dehydration, infection, kidney disease and thyroid problems can create or intensify similar symptoms. If you are not receiving radiation treatment, a clinician should clarify what exposure occurred and whether another cause better explains the fatigue. Related conditions include [Anaemia](/conditions/anaemia/), [Dehydration](/conditions/dehydration/) and [Chronic Kidney Disease](/conditions/chronic-kidney-disease/).

Plan demanding tasks for the part of the day when you have more energy, use short activity periods, and rest before you become exhausted. Keep a simple record of sleep, appetite, fluids, medicines and activity. Gentle movement may help if your treatment team says it is appropriate. Eat regular nourishing meals and ask your clinician whether blood tests or a medication review are needed. Do not drive or operate equipment if fatigue affects alertness.

Contact your treatment team promptly if fatigue is suddenly worse, prevents basic self-care, or comes with fever, breathlessness, chest pain, fainting, confusion, severe dizziness, unusual bleeding or inability to keep fluids down. Urgent help is appropriate for collapse, severe breathing difficulty or new confusion. Persistent fatigue also merits review because treatable contributors may be present.

Could my fatigue be related to treatment, anaemia, dehydration, sleep or another condition? Should my blood count or medicines be checked? What activity level is safe? Which changes should I report between appointments?