Symptoms
- Tiredness not relieved by rest
- Difficulty concentrating ("brain fog")
- Needing caffeine to function
- Low motivation or mood alongside fatigue
Tiredness & low energy: symptoms, causes & treatment
Persistent tiredness is one of the most common reasons people see a GP. Often it’s lifestyle and recoverable; sometimes it’s a sign of something checkable — low iron, thyroid issues, low vitamin D, sleep apnoea or low mood.
Editorial information by Kaiser Khan. Not clinically reviewed.
Why it happens
Sleep debt and poor sleep quality top the list, followed by stress, low mood, iron deficiency (especially in menstruating women), thyroid problems, vitamin D or B12 deficiency, alcohol, and sleep apnoea — especially with snoring and daytime sleepiness.
Treatment
A GP consultation can take a proper history and arrange targeted blood tests rather than guesswork. Treating an identified cause — iron, thyroid, sleep apnoea, mood — usually transforms energy.
Self-care that helps
Protect a consistent 7–9 hour sleep window; morning daylight; regular movement; limit alcohol and late caffeine; consider vitamin D in autumn/winter as per UK guidance.
When to get help
Fatigue with weight loss, night sweats, breathlessness, chest pain, or that persists beyond a few weeks despite good sleep deserves assessment — don’t just push through.
Go deeper
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