What should you know about fatigue?

Fatigue may feel like low physical energy, slower thinking, or an effort to complete ordinary tasks. Notice whether it began suddenly or gradually, whether rest helps, and whether it affects work, driving, exercise, or self-care. Poor sleep, emotional strain, a recent infection, low fluid intake, and some medicines can all contribute. Fatigue is also a presentation of conditions such as anaemia, coeliac disease, chronic kidney disease, COVID-19, burnout, alcohol use disorder, dehydration, or chronic fatigue syndrome; these conditions have different accompanying features and need different assessments.

Keep a short record of sleep, meals, fluids, activity, mood, medicines, and other symptoms. Aim for a regular sleep and wake time, eat balanced meals, drink regularly, and use gentle activity if it does not worsen your symptoms. Avoid using alcohol as a sleep aid. Arrange a GP consultation if fatigue persists, keeps returning, or limits daily life; take your symptom record and a list of medicines and supplements.

Seek urgent help for fatigue with chest pain, severe breathlessness, fainting, new confusion, sudden weakness, or signs of a serious allergic reaction. Contact a clinician promptly if you have black or bloody stools, persistent vomiting, marked dehydration, a high fever, or rapidly worsening symptoms. A clinician can examine you and decide whether blood tests or other checks are appropriate.

Could my sleep, medicines, mood, diet, or recent illness explain this fatigue? Which symptoms should I track? Do I need an examination or blood tests? What level of activity is suitable while I recover?