Possible causes
- Environment – a warm bedroom, a heavy duvet, non-breathable pyjamas.
- Alcohol and spicy food in the evening – widen blood vessels and raise body temperature.
- Hormonal changes – perimenopause and menopause in women, low testosterone in men.
- Stress and anxiety – nervous system activation can also show up at night.
- Medication – some antidepressants, diabetes medication or hormone therapy.
- Medical causes – infections, an overactive thyroid, night-time hypoglycaemia or sleep apnea.
What to check
- TSH and fT4 – an overactive thyroid increases heat production.
- Glucose – especially if you take diabetes medication.
- Blood count and CRP – for long-term sweating, to assess inflammation and infection.
- Hormones – for women estradiol and FSH depending on age and cycle; for men testosterone.
What helps
- A cool bedroom – around 17–19 °C, a light cover, breathable clothing.
- No alcohol or heavy meals in the evening – at least 2–3 hours before bed.
- Wind down before sleep – slow breathing, relaxation and fewer screens.
- Regular exercise – improves temperature regulation and sleep.
- In perimenopause, work with your doctor – effective hormonal and non-hormonal options exist.
When to see a doctor
See a doctor if night sweats soak your bed, recur for several weeks, or come with fever, unexplained weight loss, swollen lymph nodes, cough, palpitations or marked fatigue.