You wake up with damp sheets, a soaked T-shirt and a vague feeling of betrayal by your own body. Night sweats are very common, and in most cases the cause is ordinary. But a few patterns are worth taking seriously, so it helps to know the difference.
Health note: This article is for general information only and isn’t medical advice. Check with a doctor before starting a new treatment, device or exercise routine, especially if you have a health condition, pain or symptoms that worry you, and stop if something doesn’t feel right. See our full medical disclaimer.
What Counts as Night Sweats?
Real night sweats mean you sweat enough to soak your nightclothes or bedding, not just feel a bit warm under a heavy duvet. If a cooler room fixes it, that is usually your environment. If you are drenched even when the room is cool, it is worth looking further.
Everyday Causes
- A warm bedroom or heavy bedding. The most common and easiest to fix. Memory foam and synthetic sheets trap heat.
- Alcohol, caffeine or spicy food late in the day. All can raise body temperature or trigger sweating.
- Heavy exercise close to bedtime. Your core temperature stays raised for a while.
- Stress and anxiety. An overactive stress response can cause sweating at night.
- Sleep apnea. Repeated breathing pauses can trigger sweating. See signs of sleep apnea if you snore too.
Medication Causes
Several common medicines list sweating as a side effect, including some antidepressants, some pain and fever medicines, steroids, certain hormone treatments and some diabetes drugs. Do not stop a prescription on your own. If the timing lines up with a new medicine, tell your doctor or pharmacist.
Hormonal Causes
Menopause and perimenopause are well-known causes of night sweats and hot flashes. In men, low testosterone or some prostate treatments can cause them too. An overactive thyroid speeds up your metabolism and can make you sweat more at any hour.
Medical Causes Worth Ruling Out
Less often, night sweats point to an infection, low blood sugar overnight in people on diabetes medication, or other conditions. Persistent drenching night sweats with other symptoms can occasionally be linked to more serious illness, which is why a doctor should look at them rather than you guessing.
When to See a Doctor
Get checked if you notice any of the following:
- Night sweats that happen regularly and soak your sheets
- Fever or chills
- Unexplained weight loss
- Persistent cough, swollen glands or ongoing fatigue
- New sweating after starting a medicine
- Chest pain or a racing heart
Most people who go in turn out to have something simple. The point is to rule out the rest.
How to Cool Your Nights
- Keep the bedroom around 16 to 19 degrees Celsius (60 to 67 Fahrenheit) if you can.
- Use breathable bedding such as cotton, linen or bamboo, and a lighter duvet or layers you can peel off.
- Wear loose, moisture-wicking sleepwear.
- Skip alcohol and big spicy meals close to bedtime.
- Keep a spare T-shirt and a towel by the bed so a change is quick.
- If sweating is heavy in general, our guide to hyperhidrosis explains the treatment options.
Common Questions
Are night sweats always serious? No. Most are caused by heat, lifestyle or hormones. It is the persistent, drenching kind with other symptoms that needs attention.
Can anxiety cause them? Yes, stress can trigger sweating and disturb sleep.
Are night sweats and hot flashes the same? They are closely related. Night sweats are hot flashes that happen in your sleep.
The Bottom Line
A hot room is the most likely culprit and the easiest fix. If your nights stay soaked despite a cool room, or come with fever, weight loss or other new symptoms, book a check-up and stop guessing.