Q: Why do I sweat in my sleep?
You fall asleep at a comfortable temperature — not too hot, not too cold — only to wake up a few hours later drenched in sweat. Sometimes your pajamas are soaked and you may even feel the need to change your sheets before going back to sleep. You’re wet, uncomfortable, and maybe a little worried. What is going on?
Night sweats are “a weird symptom because they’re usually harmless, but occasionally they’re not, so it’s definitely something we always take seriously,” said Dr Kate Rowland, an associate professor of family medicine at Rush University Medical College. in Chicago.
Sweating during sleep is a relatively common complaint that can affect people across the age and gender spectrum, said Dr. Rowland. Surveys of adults who visited their primary care physician for unrelated reasons have shown that between: 10 and 40 percent say they at least occasionally suffer from night sweats.
There are many possible causes of night sweats, so if a patient Dr. Rowland says they wake up soaked at night, wanting to know more.
“One of the first things we ask is how warm is your room?” she said. “When you wake up and you say, ‘Oh my gosh, it’s hot in this room,’ we say, ‘Well, adjust the temperature accordingly.'”
The National Sleep Foundation recommends a bedroom temperature between 60 and 67 degrees for a comfortable night’s sleep. If you can’t keep your bedroom so cool, you can try adding a strategically placed fansaid Dr. Rowland. Switching to lighter bedding or nightwear may also help.
“It’s tricky because the temperature at which you’re most comfortable to fall asleep may not be the most comfortable to stay asleep,” she said.
indeed, are cozy and warm is helpful for falling asleep, said William Wisden, a professor of life sciences and a sleep researcher at Imperial College London. Just like other mammals build nests before going to sleep, we put on pajamas and curl up under blankets before going to sleep, and studies have shown that people fall asleep faster after a warm bath, shower or foot bath, he said. “But if you get too warm at night and you have a really thick duvet on, your body will naturally try to regulate the temperature.” And sweating is one of your body’s tools for cooling down, he said.
If you sweat at night, even after lowering your room temperature or taking other steps to cool your sleep setup, it’s worth seeing a healthcare provider to consider possible medical causes. They will likely ask how long and how often you have had night sweats, if it is mild if your pajamas are drenched, and if you have additional symptoms such as fever, weight loss, fatigue, cough, shortness of breath, or pain — or any other symptoms that just don’t seem quite right for that patient,” said Dr. Rowland.
Any infection that causes a fever can lead to daytime or nighttime sweating, but a number of serious illnesses, including tuberculosis, HIV infection, endocarditis (inflammation of the lining of your heart valves and chambers), malaria, and mononucleosis, have been specifically linked brought with Night sweats. And rarely, severe night sweats can be a symptom of cancers like lymphoma, said Dr. Rowland.
“You can narrow things down pretty quickly with a few lab tests and a few detective-style questions,” says Dr. Andrea Matsumura, a sleep medicine physician at The Oregon Clinic in Portland and a spokeswoman for the American Academy of Sleep Medicine.
dr. Matsumura said she often sees patients in menopause whose sleep is fragmented by: Night sweat; along with hot flashes, which often start several years before the last menstrual cycle and can persevere for years afterwards. If night sweats in menopause are interfering with a good night’s sleep, it’s worth talking to your health care provider about treatment options, she said.
In her sleep medication patients, excessive sweating occurs at night “usually because they have some sort of abnormal breathing in their sleep, and that’s a sign of sleep apneasaid Dr. Matsumura. Studies have found: that night sweats may also be associated with insomnia, restless legs syndrome, and narcolepsy.
Finally, many medications can cause night sweats. Among the most common culprits are antidepressants, diabetes medications, and certain hormonal therapies. If a drug appears to be a likely cause, Dr. Rowland talks to her patients about the risks and benefits of stopping or changing the medication, depending on how bothersome the night sweats are.
But very often, Dr. Rowland said she can’t pinpoint the cause of night sweats in her patients, “and that’s always frustrating.” In those cases, she emphasized that patients should let her know if their night sweats are getting worse or if they develop new symptoms.
Otherwise, sweating in sleep may just be part of how your body regulates its temperature at night, said Dr. Rowland. Our usual circadian rhythm involves a small, steady drop in body temperature throughout the night, and sweating is a “normal, physiological response” that can help you reach or maintain that lower temperature, she added. And “some people sweat more than other people.”
Normal or not, night sweats can be uncomfortable and disrupt sleep. In addition to lowering the temperature in your bedroom and adjusting your nightwear and bedding, Dr. Matsumura recommends avoiding exercise, drinking alcohol or hot drinks, and eating a heavy meal too close to bedtime, all of which she says can lead to sweating at night.
If you normally sleep with a partner, you can also try sleeping separately for a few nights to see if that helps, said Dr. Rowland. “Sometimes that other person is like having a 180- or 200-pound, 98-degree oven next to you and can also affect your temperature control at night.”
Very often, dealing with night sweats means conducting a series of individual experiments to take a more comfortable nap. “There’s nothing magical,” said Dr. Rowland. “Different things work for different people.”
Alice Callahan is an Oregon health and science journalist and a regular contributor to The New York Times.