Symptoms
- Tiredness not relieved by rest
- Difficulty concentrating ("brain fog")
- Needing caffeine to function
- Low motivation or mood alongside fatigue
Tiredness & low energy
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.
Medically reviewed by Dr [GP Name], General Practitioner GMC 0000000
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
Related guides
Seeing a doctor online in the UK: what to expect and how to spot a safe service
What online GP consultations can and can't do, what the 2025 rule changes mean, and the red flags that separate safe providers from risky ones.
Vitamin D in the UK: why most of us need to think about it
UK sunlight can't supply vitamin D for half the year. A GP-reviewed guide to who needs a supplement, how much, and what it does.
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