About this symptom
Night sweats are sweating during sleep. It is normal to sweat at night if your room or bedding is too hot. The kind that needs attention keeps happening, wakes you or worries you.
Common causes include menopause, anxiety, some medicines, low blood sugar, and alcohol or drug use. Less often the cause is an infection such as TB or a cancer such as lymphoma. Sometimes the cause is never found, and many people need no treatment.
Possible causes
This is not a diagnosis. These are the causes doctors think about, with the ones that are most urgent to rule out first.
- TuberculosisNight sweats or fever with a cough that has lasted more than 3 weeks, constant tiredness, reduced appetite and weight loss.Read about it
- LymphomaA painless lump in the neck, armpit or groin, with night sweats, fever, itchy skin, breathlessness or weight loss.
- Low blood sugarA known cause of sweating in sleep. If you have diabetes and wake in a sweat, tell your doctor, as it may be low sugar.
- MenopauseHot flushes and night sweats, together with changing periods, sleep problems and mood changes.Read about it
- AnxietySweating tied to worry or stress, which may also happen in the daytime.Read about it
- Some medicinesSome antidepressants, steroids and painkillers can cause night sweats. Do not stop a medicine yourself: ask your doctor.
- Alcohol or drug useAlcohol or drug use, or stopping alcohol or certain drugs suddenly (withdrawal), can cause sweating.
- A hot room or heavy beddingSweating at night is normal if the room or bedding is too hot, and settles when you cool down.
When to get help
See a doctor soon if you have:
- Night sweats that keep happening, wake you or worry you
- Night sweats with a very high temperature, feeling hot, cold or shivery, a cough or diarrhoea
- Night sweats with weight loss for no reason
- A cough that has lasted more than 3 weeks
- A painless lump or swelling in the neck, armpit or groin
- Sweats that began after you started a new medicine
If the sweats happen only on hot nights or under heavy bedding, and nothing else is wrong, they can wait.
What you can do at home
Do
- Make the bedroom a little cooler, with a fan or an open window
- Use lighter bedding and nightclothes
- Drink water after heavy sweating
- Note when the sweats happen, how often, and any other symptoms
Do not
- Do not stop or change a medicine yourself if you think it is the cause: ask your doctor
- Do not drink much alcohol or use drugs, which can cause sweating
- Do not put it down to heat if it keeps happening or comes with fever, cough or weight loss
What the doctor will do
The doctor will ask how often the sweats happen, when they began, and whether you have a fever, cough, diarrhoea or weight loss. They will ask about your periods, stress, alcohol and every medicine you take. They will examine you, including feeling for lumps in the neck, armpits and groin.
Night sweats alone often need no treatment, but the doctor will check for other symptoms. If a medicine may be the cause, they may prescribe a different one. If something else is suspected, tests may include:
- Blood tests
- A chest X-ray and tests of phlegm, if TB is suspected
- Scans, or a (a small sample of tissue) from a swollen gland, if a lump is found
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Night sweats always mean cancer.”What is true?
Fact
Most night sweats have common causes such as menopause, anxiety, certain medicines, low blood sugar, and alcohol or drug use. TB and lymphoma can cause them, so see a doctor if they keep happening or come with fever, cough or weight loss.
Myth“It is just body heat, so it needs nothing.”What is true?
Fact
Sweating at night is normal if the room or bedding is too hot. But sweating that keeps happening, wakes you, or comes with fever, cough, diarrhoea or weight loss is worth checking.
Myth“Only women going through menopause get night sweats.”What is true?
Fact
Menopause is a common cause, but night sweats can also come from anxiety, medicines, low blood sugar, alcohol or drug use, TB and lymphoma, and these affect men as well as women.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Are night sweats normal?
Sweating at night is normal if your room or bedding is too hot. See a doctor if you regularly have night sweats that wake you up or worry you, or if they come with a very high temperature, a cough, diarrhoea or weight loss.
Can night sweats be a sign of TB?
Yes. TB can cause fever or night sweats along with a cough that lasts more than 3 weeks, constant tiredness, reduced appetite and weight loss. If you have these, see a doctor. Tests may include a chest X-ray and a test of the phlegm you cough up.
Can night sweats be a sign of lymphoma?
They can be, usually along with a painless lump in the neck, armpit or groin, a fever, itchy skin, breathlessness or weight loss. These symptoms are common and have many causes, so having them does not mean you have lymphoma, but they should be checked.
Can my medicines cause night sweats?
Yes. Some antidepressants, steroids and painkillers can. Do not stop a medicine yourself. Tell your doctor, who may prescribe a different one if the medicine is the cause.
