What should you know about systemic fatigue?

Fatigue may feel different from ordinary sleepiness: rest may not restore energy, and thinking, exercise or routine tasks may take more effort. It can follow an infection such as COVID-19, poor sleep, dehydration, emotional overload or alcohol use. It may also accompany anaemia, coeliac disease, chronic kidney disease or a longer-lasting illness such as chronic fatigue syndrome. Fatigue is a symptom rather than a diagnosis, so its pattern matters: note when it started, whether it fluctuates, what worsens it and whether pain, fever, weight change, breathlessness or low mood occur with it.

Keep a brief record of sleep, meals, fluids, activity, medicines and symptoms. Aim for a regular sleep routine, gentle activity within your capacity and steady meals and fluids. Avoid trying to push through a marked crash, and review medicines or supplements with a clinician rather than stopping prescribed treatment alone. Arrange an assessment when fatigue persists, interferes with work or self-care, or has no clear explanation. The clinician may ask about sleep, mood, bleeding, diet, infection and long-term conditions before deciding whether tests are useful.

Seek urgent help for severe breathlessness, chest pain, fainting, new confusion, sudden weakness, black or bloody stools, or inability to keep fluids down. Prompt assessment is also needed when fatigue comes with a high fever, rapidly worsening weakness, marked dehydration or thoughts of self-harm. Do not drive if exhaustion makes you unsafe to concentrate.

Ask what pattern of fatigue you should track, whether sleep or mood may be contributing, which medicines could be involved, and whether symptoms suggest anaemia, thyroid or kidney problems. Mention snoring, unrefreshing sleep, dietary restriction, bleeding and recent infection.