The short answer: night sweats are episodes of heavy sweating in your sleep that soak your night clothes and bedding even when the room is cool. The most common causes are menopause, anxiety, some medicines, low blood sugar and alcohol. Most people who have them don’t have a serious illness. See a doctor if they come with weight loss you can’t explain, a fever or swollen glands.
Sweating a little when the room is warm or your duvet is heavy is normal. This guide covers the kind that wakes you up wet.
What are night sweats?
Night sweats are when you sweat so much that your night clothes and bedding are soaking wet, even though where you’re sleeping is cool. That’s the NHS definition. Cleveland Clinic adds that you may feel a sudden wave of heat in your neck, chest and upper body, a faster heartbeat, and then a chill once the sweating stops.
They’re common. A 2020 review in American Family Physician reports that 10% to 41% of patients in primary care have them, with the highest rates between ages 41 and 55. Many people never mention them to a doctor unless asked.
What causes night sweats?
The most common causes of night sweats are menopause, anxiety, medicines, low blood sugar and alcohol or drug use, according to the NHS. Sometimes no cause is found. Here’s the fuller picture, from the NHS, Cleveland Clinic and the American Family Physician review:
| Cause | Clues that point to it | How common or serious |
|---|---|---|
| Perimenopause and menopause | Changing periods, hot flashes in the day too | One of the most common causes |
| Medicines | Sweats began after starting or changing a medicine | Common; see the table below |
| Anxiety, panic or ongoing stress | Worry, racing heart, panic attacks | Common; depression and PTSD are linked too |
| Low blood sugar at night | Diabetes treated with insulin or tablets | Worth checking if you have diabetes |
| Alcohol, smoking or drug use | Sweats after drinking; three or more drinks a day was linked to night sweats in one study | Common and changeable |
| Infections | Fever, chills, cough; flu and COVID-19 can do it, as can tuberculosis, HIV and heart valve infection | A fever points this way; tests can find the cause |
| Obstructive sleep apnea | Loud snoring, gasping, daytime sleepiness | About a third of people with sleep apnea in an Icelandic study had night sweats, three times the rate of people without it |
| Overactive thyroid | Weight loss, tremor, fast heartbeat, feeling hot all the time | Found with a simple blood test |
| Pregnancy, after birth or before a period | Timing that follows your cycle or the weeks after a baby | Usually settles as hormones level out |
| Low testosterone in men | Low sex drive, erection problems | Less common |
| Hyperhidrosis | Sweating too much day and night, for no clear reason | Harmless, though it can be a nuisance |
| Lymphoma, leukemia and other cancers | Weight loss, fevers, swollen glands, easy bruising | Rare, and night sweats are rarely the only sign |
The honest framing matters here. The American Family Physician review says that although many serious causes have been described, most people with persistent night sweats in primary care don’t have a serious underlying disorder. In a study that followed 1,534 people older than 65 for about seven and a half years, those with night sweats were no more likely to die, or to die sooner, than those without them. That held for people with severe sweats too.
What causes night sweats in women?
In women, night sweats are most often caused by shifts in estrogen and progesterone, which help your body control its temperature. Cleveland Clinic names three common times: perimenopause and menopause, pregnancy and the weeks after giving birth, and the days before a period, when estrogen drops.
Menopause is the big one. The review notes that hot flashes may lower the temperature at which your body starts sweating, so you sweat more often. If your periods are changing too, our guide to perimenopause symptoms shows the other signs, and perimenopause vs menopause explains which stage you may be in. All the other causes in the table apply to women as well.
Which medicines can cause night sweats?
Many common medicines can cause night sweats, including some antidepressants, steroids, painkillers and diabetes medicines. The American Family Physician review lists these as having at least moderate-quality evidence behind the link:
| Type of medicine | Examples from the review |
|---|---|
| Pain and fever relief | Aspirin and other salicylates, NSAIDs such as ibuprofen, meperidine |
| Diabetes | Insulin and diabetes tablets (often through low blood sugar) |
| Antidepressants | SSRIs |
| Heart and blood pressure | Beta blockers |
| Cold and cough | Decongestants, cough suppressants |
| Other | Anticholinergics, cholinesterase inhibitors (used for dementia), niacin |
Cleveland Clinic adds some migraine medicines, opioid painkillers, breast cancer treatments and some blood pressure medicines. If you suspect a medicine, talk to the doctor who prescribed it before you change anything. The NHS says a GP may be able to prescribe a different one if it seems to be the cause.
Are night sweats a sign of cancer?
Night sweats can be a sign of cancer, most often lymphoma or leukemia, but they are rarely the only sign. The American Family Physician review says night sweats on their own carry no extra warning about a cancer’s outlook. What raises concern is the company they keep: unexplained weight loss, fevers, swollen glands that don’t go away, easy bruising or bleeding, and tiredness that feels like being unwell.
Cancer treatment can cause night sweats too. The National Cancer Institute lists surgery that brings on early menopause, chemotherapy, hormone therapy and radiation as possible causes.
When should you worry about night sweats?
See a doctor about night sweats if they happen regularly and wake you, or if they come with weight loss, fever or swollen glands. These are the signs the NHS and the American Family Physician review single out:
- Losing weight without trying. Doctors generally count losing more than 5% of your body weight in 6 to 12 months as significant.
- A fever, or feeling hot, cold or shivery, especially if it keeps coming back.
- Swollen glands in your neck, armpits or groin. The review says lumps that last longer than four to six weeks alongside night sweats should be checked promptly.
- A cough or diarrhea that goes with the sweats.
- Loud snoring or gasping in your sleep, which can point to sleep apnea.
- Sweats that worry you or keep waking you up.
The NHS says most people with night sweats won’t need treatment, but a doctor will want to look for other symptoms. If nothing obvious turns up, the review suggests first tests such as a blood count, a thyroid test, a tuberculosis test, an HIV test, an inflammation marker and a chest X-ray. Before your visit, keep a short diary: the nights you sweated, what you drank, any new medicines and your temperature.
How do you stop night sweats tonight?
To get through tonight, make your bed and your room cooler and easy to adjust. Most of these steps come from Cleveland Clinic, the NHS and the National Cancer Institute:
- Cool the room. Use a fan, open a window or turn on the air conditioning.
- Layer your bedding. Use light layers you can push off in the night, instead of one heavy duvet. Cooling-gel pillows and mattress covers are an option.
- Wear loose cotton or linen. Lightweight pajamas let heat escape.
- Keep cold water by the bed to sip when you wake hot.
- Keep a spare set within reach. Dry pajamas and a towel by the bed mean a quick change instead of a full wake-up.
- Go easy in the evening on spicy food, caffeine and alcohol, which can all make you sweat.
For more on cooling down during the day, see how to stop hot flashes. If the sweats are costing you sleep, our guide to menopause and sleep covers the treatment with the best evidence for insomnia.
How do you stop night sweats from menopause?
For night sweats caused by menopause, a doctor can offer hormone and non-hormone treatments, plus a talking therapy. Cleveland Clinic and the NHS list these:
- Hormone therapy (HRT), which replaces the hormones that fall in menopause. All hormone therapies carry some risks, and your doctor can help you weigh them. Our perimenopause symptoms guide sets out the NHS figures.
- Non-hormonal medicines for people who can’t or don’t want to use hormones: some antidepressants, antiseizure medicines, oxybutynin, clonidine, fezolinetant and paroxetine.
- Talking therapy. The NHS says cognitive behavioral therapy (CBT) can help manage hot flashes and night sweats, and the National Cancer Institute lists relaxation and hypnosis as well.
Which one suits you depends on your health history. Bring your sweat diary and a list of your current medicines to the appointment.
Food won’t switch night sweats off. If you’d like help with meals through the change, our guide to what to eat during menopause covers the basics, and the Menopause Meal Plan below plans four weeks for you.
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Quick questions
Are night sweats normal?
Some sweating at night is normal if your room or bedding is too warm. Night sweats are different: you wake with your night clothes and sheets soaked even though the room is cool. They’re common, reported by 10% to 41% of primary care patients in one review, and most have a harmless cause.
Are night sweats a sign of cancer?
Rarely on their own. Lymphoma and leukemia can cause night sweats, but a 2020 review in American Family Physician says they are rarely the only symptom. See a doctor promptly if night sweats come with weight loss you can’t explain, repeated fevers, swollen glands that last for weeks, or easy bruising.
Can night sweats be caused by anxiety?
Yes. The NHS lists anxiety as one of the most common causes of night sweats, and Cleveland Clinic says panic disorder and constant stress can trigger sweating in your sleep too. A 2020 review also links depression, panic attacks and post-traumatic stress disorder to night sweats. If worry is keeping you up, mention it to your doctor.
Are night sweats the same as hot flashes?
In menopause, night sweats are hot flashes that happen while you sleep, according to the Office on Women’s Health. The same sudden heat in the face, neck and chest leads to heavy sweating. Night sweats can also have causes that have nothing to do with menopause, such as medicines, infections or sleep apnea.
What causes night sweats in men?
In men, common causes include anxiety, alcohol, medicines such as some antidepressants and painkillers, infections and sleep apnea. A 2020 review also lists low testosterone, which can cause hot flashes and sweating. See a doctor if the sweats come with weight loss, fever or swollen glands.
Are night sweats a sign of diabetes?
Not usually on their own. In people who already have diabetes, low blood sugar at night can cause sweating, especially with insulin or some diabetes tablets. Studies on diabetes itself and night sweats disagree. If you have diabetes and often wake up sweaty, tell your diabetes care team so they can check your levels overnight.
This article is general information, not medical advice. Night sweats have many causes, and only a doctor can find yours. If you take a medicine you think may be causing them, talk to the doctor who prescribed it before you change anything. If you have night sweats with weight loss, fever or swollen glands, see a doctor soon.
Sources
- NHS. Night sweats
- Cleveland Clinic. Night Sweats: Menopause, Other Causes and Treatment
- Bryce C. Persistent Night Sweats: Diagnostic Evaluation. Am Fam Physician, 2020
- National Cancer Institute. Hot Flashes and Night Sweats (PDQ), Patient Version
- NHS. Things you can do to help menopause and perimenopause symptoms
- Office on Women’s Health. Menopause symptoms and relief