General
Night sweats
Sweating heavily during sleep, often enough to soak your nightclothes or bedding.
Education and reference only. This explains the common causes of night sweats and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is night sweats?
Night sweats are episodes of heavy sweating during sleep that leave you damp or soaked, going beyond simply feeling warm because of bedding or a hot room. They are very common and most often harmless, linked to things like the menopause, anxiety or an overactive thyroid.
- Get urgent help: Drenching night sweats with unexplained weight loss, a persistent fever, or a new painless lump – these need assessment to rule out lymphoma, TB or other serious illness. Night sweats together with a persistent cough or coughing up blood.
- Self-care: Simple changes to your sleep environment can ease many night sweats.
About night sweats
Night sweats are episodes of heavy sweating during sleep that leave you damp or soaked, going beyond simply feeling warm because of bedding or a hot room. They are very common and most often harmless, linked to things like the menopause, anxiety or an overactive thyroid. Occasionally, though, drenching night sweats are a sign of an infection or, less commonly, a more serious illness, particularly when they come alongside unexplained weight loss, fevers or a new lump. Noticing how often they happen, whether they wake you, and what other symptoms come with them helps you and a clinician judge how concerning they are.
When to get help
Call 999 or go to A&E if night sweats comes with any of these warning signs:
- Drenching night sweats with unexplained weight loss, a persistent fever, or a new painless lump – these need assessment to rule out lymphoma, TB or other serious illness.
- Night sweats together with a persistent cough or coughing up blood.
When to see a doctor
See a doctor if night sweats keep happening, regularly disturb your sleep, or you cannot explain them by a hot room or heavy bedding. It is particularly important to get checked if they come with weight loss, ongoing fevers, a new lump, or feeling generally unwell. Around the menopause, if hot flushes and night sweats are affecting your quality of life, a clinician can talk through the options that might help.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of night sweats
Night sweats has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
Simple changes to your sleep environment can ease many night sweats. Keep your bedroom cool and well aired, use light, breathable cotton bedding and nightclothes, and keep a glass of water nearby. Cutting back on alcohol, caffeine and spicy food in the evening can help, as can winding down before bed to settle stress. Keeping a short diary of when the sweats happen and anything that seems to bring them on can be useful to share with a clinician if they persist.
Answers
Night sweats: frequently asked questions
Are night sweats usually a sign of something serious?
Most of the time they are not, and are linked to things like the menopause, anxiety or an overactive thyroid. They are more of a concern when they are drenching and come with unexplained weight loss, persistent fevers or a new lump, which should be checked.
How can I tell night sweats apart from just being too warm in bed?
True night sweats are heavy enough to soak your nightclothes or bedding and happen even when the room is cool and the covers are light. Simply feeling warm because of a hot room or thick duvet usually settles when you adjust them.
Can the menopause cause night sweats?
Yes. Changing hormone levels around the menopause commonly cause hot flushes that strike at night as sweats. If they are disrupting your sleep and daily life, a clinician can discuss the options that may help.
What lifestyle changes can reduce night sweats?
Keeping the bedroom cool, using light cotton bedding, and cutting back on alcohol, caffeine and spicy food in the evening can all help. Winding down to ease stress before bed may also reduce how often they happen.
Sources
Where this is drawn from
- NICE CKS: Menopause.
- Macmillan Cancer Support.
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