Why am I so tired?
General information only. This article explains the basics and is not medical advice. For anything about your own health, talk to a doctor or other qualified professional.
Quick answer
Feeling tired all the time is most often caused by not enough or poor-quality sleep, stress, an irregular routine, too much caffeine or alcohol, not enough physical activity or dehydration. Persistent tiredness that doesn’t improve with rest is worth checking with a doctor.
Tiredness is one of the most common reasons people see a doctor. Usually it has an everyday explanation, and small changes help.
Everyday causes
| Cause | What to look at |
|---|---|
| Sleep | Fewer than 7 hours, late nights, or scrolling in bed |
| Irregular schedule | Shift work, jet lag, very different weekend sleep times |
| Stress and worry | Keeps the mind busy and disrupts sleep |
| Caffeine and alcohol | Caffeine late in the day and alcohol at night both reduce sleep quality |
| Too little activity | Being inactive can make you feel more tired, not less |
| Diet and fluids | Skipping meals, lots of sugary snacks, or not drinking enough water |
Health-related causes
Persistent tiredness can sometimes be a sign of a health issue, such as:
- Iron-deficiency anemia
- Underactive thyroid
- Depression or anxiety
- Sleep apnea, where breathing stops briefly during sleep
- Diabetes
- After an infection, such as flu or COVID-19
Only a doctor can work out whether a condition is involved, often with a simple blood test.
When to see a doctor
Health services advise seeing a doctor if tiredness lasts for several weeks, doesn’t improve with rest, or comes with other symptoms such as unexplained weight loss, shortness of breath, low mood or feeling unwell.
Small changes that often help
Many people feel better by keeping a regular sleep schedule, getting daylight and movement during the day, cutting caffeine after midday, and limiting alcohol. See why sleep is important and how to sleep better.
Sources
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