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10 causes of night sweats—and when to worry

True night sweats go beyond a hot bedroom or heavy sleepwear

What are night sweats? | What causes night sweats? | When to see a doctor | How to stop night sweats

You expect to sweat when you’re exercising or spending time outdoors on a hot summer day. But, waking up in the morning with damp pajamas and sheets can be disconcerting. Although night sweats are troubling, experts say they are also fairly common. In one study, 41% of participants reported night sweats.

What’s behind perspiration while you’re sleeping? “Night sweats can be caused by a wide variety of medical conditions, including infections, medications, hormones, stress, and anxiety,” says Cassie Majestic, MD, emergency medicine physician in Orange, California, founder of drmajestic.com.

What are night sweats?

True night sweats are more than waking up hot when you accidentally leave the thermostat turned up too high. Also known as sleep hyperhidrosis, night sweats occur over the course of several weeks, even when the temperature in your bedroom is cool. It’s not just light perspiration—it’s feeling like your bedclothes are drenched in moisture.

“Sometimes night sweats can be caused because your bedroom is hot or you have too many blankets on your bed,” says Saralyn Mark, MD, an endocrinologist, geriatrician, and women’s health specialist and founder of SolaMed Solutions. “Other times, it can be your body’s way of telling you that something is happening with your health.” Meaning, an underlying medical condition or certain medications could be a potential cause of night sweats. 

10 causes of night sweats

Some common causes of night sweats include:

1. Menopause

Up to 85% of women going through perimenopause and menopause experience severe hot flashes—sudden intense changes in body temperature (mainly bursts of body heat or hot flushes)—and often report that these symptoms of menopause are worse at night.

“Hot flashes and night sweats occur due to changing hormone levels,” says Dr. Mark. If your family physician finds that night sweats are caused by changes in estrogen and progesterone production, ask about hormone therapy, which can often relieve menopause symptoms—namely the hot flashes that cause night sweats.

2. Medications

According to Dr. Majestic, night sweats are a side effect of many common medications including:

Check with your primary care physician or pharmacist if you worry that night sweats could be a side effect of your medication.

3. Stress

Stress and anxiety are also common causes of night sweats, says Dr. Majestic. “Typically there will be other symptoms such as mood changes, trouble sleeping, extreme sadness or hyperactivity, or constant fatigue,” she says.

If stress or anxiety is the cause of your night sweats, your physician might recommend talk therapy, an antidepressant, or making lifestyle changes. 

4. Overactive thyroid

Night sweats can also be a symptom of endocrine disorders, like a thyroid problem, according to Dr. Mark. An overactive thyroid (also known as hyperthyroidism) is a common cause of night sweats, excessive sweating, anxiety, and sleep problems. Simple thyroid blood tests can determine if a thyroid disease could be causing your symptoms so your physician can prescribe medication to relieve symptoms.

5. Acid reflux

Some patients with acid reflux or the more severe gastroesophageal reflux disease (GERD) can experience both nighttime heartburn and excessive sweating.

“People with GERD experience heartburn at least twice a week for several weeks,” Dr. Mark says. “If you have GERD, and it’s not well-controlled, your doctor might recommend taking an H2 blocker such as Pepcid AC or Tagamet HB.”

6. Spicy foods

Certain spicy foods that contain capsaicin trigger the same nerves that make you feel warm, triggering sweating to cool down. Avoiding these too close to bedtime can help.

7. Alcohol

A night cap might seem like a good way to relax. But, if you’ve been waking up sweaty, it might make sense to switch to a seltzer. Alcohol dilates the blood vessels in the skin, which can lead to sweating.

8. Infections

Any infection that causes a fever can lead to night sweats—whether it’s the flu, a bacterial infection like an abscess, or a serious infection like endocarditis. Some people with underlying health conditions like tuberculosis and HIV may also experience night sweats.

9. Some cancers 

Night sweats can be a symptom of certain cancers, such as non-Hodgkin’s lymphoma or leukemia. Lymphomas usually present with very severe night sweats. Though, Dr. Mark says other symptoms are typically also present such as loss of appetite and unexplained weight loss.

10. COVID-19

While not originally considered a symptom of the novel coronavirus, there are reports that night sweats come along with infection with the Omicron variant. It’s one of the signs that differentiate newer strains of the virus, along with sore throat.

When should I be concerned about night sweats?

The good news, according to Dr. Majestic is that night sweats typically aren’t a symptom of a serious medical condition.

“Night sweats are most concerning when they have been ongoing for two weeks or longer, and are accompanied by other symptoms,” Dr. Majestic says. “Be aware of symptoms such as unintentional weight loss, fevers or chills, body aches and joint pain, or enlarged lymph nodes.” These may signify an underlying medical cause.

If you notice night sweats accompanied by any of these warning signs, Dr. Majestic recommends speaking with your healthcare provider as soon as possible to screen for certain conditions. Persistent night sweats without other signs should also prompt a visit to a healthcare professional.

 During your appointment, your physician will take a detailed medical history and may also order blood tests to determine the underlying cause.

How to treat night sweats

If you’re regularly drenching the sheets in the middle of the night, one of these strategies may help to keep your night sweats at bay and improve your sleep quality.

Pay attention to your evening patterns

Are you eating, drinking alcohol, or exercising late into the evening? Dr. Majestic says each of these things could contribute to your night sweats.

“Also consider what you’re watching on television or reading before you go to bed,” Dr. Majestic says. “Is it anxiety provoking or scary? It may be a good idea to alter those behaviors. If you’re struggling with depression or anxiety, seek the help of a therapist.” Try to remove potential triggers from the hours leading up to bedtime.

Practice good sleep hygiene

Dr. Mark notes that sleeping with a fan can keep your bedroom temperature comfortable and also provide white noise.

“If you experience night sweats, try to keep your bedroom cool, wear light clothing, and use lighter blankets,” she says. 

Maintain a healthy weight

Carrying extra pounds can be associated with night sweats and also be a risk factor for developing obstructive sleep apnea, where the throat narrows, restricting your breathing. 

Try therapy

According to research, cognitive behavioral therapy can reduce menopausal symptoms like night sweats. It works by changing the way you think and feel about your symptoms to reduce the stress and anxiety surrounding your experience. For example, practicing breathing exercises and relaxation techniques can be helpful.

Research suggests that hypnosis that focuses on cool imagery (imagining the feeling of swimming in the ocean, or the cold blast of air from a freezer) may also be helpful for reducing night sweats related to menopause. 

Treat the underlying conditions

The following medications may be used to treat night sweats:

If you find that you have night sweats and wake up tired, ask your healthcare provider for a sleep test to determine if you have a sleep disorder, like sleep apnea. Losing weight might help reduce night sweats, your risk of developing sleep apnea, and improve your overall health and wellness.

“I encourage people with persistent night sweats to make an appointment with their doctor,” says Dr. Mark. “Keep a log of what’s going on in your life and what you eat or drink before bedtime. Your doctor can work with you on treatment to help you sleep comfortably through the night.