Picture it: You climb into your cosy bed, snuggle up under the duvet, and drift off to sleep…only to wake up a few hours later totally drenched in sweat.
Miserable? Yes. Also kind of scary? Yes to that, too.
Most of the time, your night sweats could be caused by something totally harmless—like the temperature of your bedroom or the fabric of your PJs. But sometimes, your sweaty nights might be a sign of an underlying condition you need to get checked out ASAP, says Dr. Neomi Shah, associate professor, pulmonary and sleep medicine, at the Icahn School of Medicine at Mount Sinai.
A general rule? If your night sweats persists for more than two or three months, get yourself checked out, says Shah—but instead of jumping to the worst-case scenario, take a peek at what commonly causes night sweats in women, and what you can do about it.
1. Your room is just too damn hot.
What’s the temperature of your bedroom right now? If it’s anything other than 15 to 20 degrees Celsius, it’s probably too hot, says Dr. W. Christopher Winter, sleep specialist and author of .
Less-breathable fabrics (like your flannel PJs) can also contribute to your sweaty sleep woes, which makes breathable cotton a better option for both your PJs and sheets.
Feeling hot can also impede your ability to actually fall asleep—in the process of drifting off, your body temperature should drop one to two degrees below normal, and it can’t do that in a warm room.
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2. You have an excessive sweating disorder.
Yes, that’s a thing—it’s called hyperhidrosis—and, according to the American Academy of Dermatology (AAD), it essentially happens when a person sweats more than necessary (yes, even while they’re sleeping).
One big difference between hyperhidrosis and run-of-the-mill sweating: Hyperhidrosis only affects specific body parts, per the AAD, specifically your palms, feet, underarms, and head. Keep in mind though, this is excessive sweating—the AAD says hyperhidrosis can interfere with daily activities (like opening doorknobs or using computers) in those who have it.
If you think you have hyperhidrosis, talk to your dermatologist—they can prescribe specific deodorants or other methods of treatment like Botox injections to block sweat glands, per the AAD.
3. You’re actually running from something in your nightmares.
This is probably the simplest explanation for those sweats: “If the sweating is chronic…sometimes it can be that the patient is totally healthy and is actually running in a dream, or frightful in a dream,” says Dr. Harry Banshick. “The sweat is the consequence of acting out the dream.”
Shah agrees, saying that anything that causes what’s called a sympathetic surge (also known as a fight-or-flight response) can lead to sweating. If you’re having ongoing, persistent nightmares, see your doctor to find out what might be causing it (stress is a big culprit).
4. Your body’s going through hormonal changes.
One of the most common causes of night sweats for women is fluctuating oestrogen levels, Nandi says. “Menopause is associated with hot flashes, so it’s not uncommon for patients to report sweating even during their sleep,” Shah says.
If you’re pregnant or on your period, those hormone fluctuations could lead to night sweats, too. However, menopause tends to cause to the most persistent sweats, and if it’s truly affecting your quality of life or sleep, Shah says it’s worth talking to your doctor about. “Sweating from menopause is unpredictable, but if you talk to your obstetric-gynaecologist about hormone replacement therapy, it could help keep your temperatures under control.”
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5. You’re taking antidepressants.
Patients taking antidepressants can definitely see an uptick in night sweats, Shah says, as certain classes of medications can cause an adrenergic reaction, which has to do with your adrenaline levels and leads to sweating. If you’re taking venlafaxine (or the brand-name Effexor) or bupropion (or its brand-named Wellbutrin, Zyban, or Aplenzin), you may experience more night sweats, Shah says.
But there’s good news if you don’t want to switch your antidepressant, as Shah says there are drugs docs can prescribe to calm down the adrenergic output, which won’t counteract your mental-health needs.
6. Your body’s fighting off an infection.
“Infections in general are related with changes in temperature because they come with fevers that will break, and that is obviously a common reason to sweat,” Shah says.
One rare infection that’s commonly associated with night sweats: tuberculosis, which can infect any part of your body but is well-known for its effect on your lungs. People with an immunocompromised condition, like HIV, can develop tuberculosis more easily, Shah says. You might start sweating in your sleep before you even start coughing or realise something is wrong, Shah says, so see a doc stat if the symptoms persist.
7. You have undiagnosed lymphoma.
Lymphoma—a cancer of part of the immune system, according to the U.S. National Library of Medicine (NLM)—can cause multiple symptoms like fever, changes in weight loss, and, yes, night sweats, says Shah. Essentially, your body recognises lymphoma as something it needs to fight off, and raises its temperature to try to do so, she adds.
While these “soaking sweats,” per the NLM, happen at night, heavy sweating might occur during the day for this, too, so get to your doctor. if you’re experiencing any other symptoms and they can test you for the condition, says Shah.
8. You’re experiencing hypoglycemia related to your diabetes medication.
Hypoglycemia occurs when blood sugar levels drop too low, and can cause a variety of symptoms including confusion, dizziness, and in some cases, night sweats. When your blood sugar level drops below a certain point, your body will use hormones, like cortisol, to try to preserve normal blood glucose levels and organ function, therefore activating the autonomic nervous system, which is in charge of your glands, explains Dr. Remos.
That activation can cause profuse sweating. Sometimes these sweats can come on suddenly and when paired with confusion may require the administration of glucose orally or intravenously, says Dr. Remos.
9. You have undiagnosed hypothyroidism.
Those with hypothyroidism have an overactive thyroid that produces more thyroid hormone than the body needs. According to the NLM, thyroid hormone can affect the way the body uses energy, and some symptoms of it include muscle weakness, mood swings, and trouble tolerating heat.
If you’re experiencing night sweats related to hypothyroidism, they may happen on a consistent schedule as opposed to randomly and will usually appear with other symptoms of the condition, says Dr. Remos.
10. You have a rare tumour in the adrenal gland known as a pheochromocytoma.
Pheochromocytomas are rare, usually benign tumours that start in the cells of the adrenal gland, according to the NLM. The symptoms associated with these tumours are episodic headaches, sweating, and tachycardia, a condition that causes a rapid heartbeat, says Dr. Remos.
These symptoms are usually caused by the excess release of hormones like adrenaline and epinephrine by the tumour, which in turn may be causing you to dampen your bed sheets at night, says Dr. Remos. “The night sweats are triggered by the excess adrenaline type hormones,” he says.
11. You’re experiencing a hormone disorder, like undiagnosed carcinoid syndrome.
Night sweats are a common symptom of hormone disorders, since they tend to throw the body’s functions out of wack. One hormone disorder which can cause night sweats is carcinoid syndrome, which refers to the group of symptoms experienced by people with carcinoid tumours, which can appear all over but tend to originate in the digestive tract.
“Getting flushed is the hallmark of the carcinoid syndrome, occurring in 84 percent of affected patients; sweating may occur concurrent with the flushing,” says Dr. Remos. “Flushing is an increased blood flow to the skin due to vasodilation and is experienced as a warmth and redness of the face and occasionally the trunk, which may be associated with sweating.”
Other symptoms related to this condition besides flushing and sweating are diarrhoea and difficulty breathing or wheezing.
12. You’re dealing with an undiagnosed neurologic condition, like post-traumatic syringomyelia.
Like hormone conditions, neurologic conditions, particularly spinal cord injury and syringomyelia, says Dr. Remos, can also cause night sweats. “The autonomic nervous system exerts involuntary control over smooth muscle like the intestine or the pupil, and glands. Damage to the spinal cord causes it to malfunction and stimulate sweat glands inappropriately,” says Dr. Remos.
Post-traumatic syringomyelia, specifically, refers to the formation of cysts in the spinal cord and can cause episodes of increased sweating, says Dr. Remos.
Remedies for night sweats
If your symptoms are mild and do not interfere with normal activities, Dr. Remos recommends simple behavioural changes, like lowering room temperature, using fans, or dressing in layers of clothing that you can easily shed. You should also avoid things that may trigger sweating, like spicy foods, and try to keep stress to a minimum. Your derm can also help prevent the sweats themselves, either by recommending clinical strength antiperspirants or Botox injections.
If you’re dealing with moderate to more severe night sweats or hot flashes related to menopause, Dr. Remos says you may want to look into menopausal hormone therapy, which uses hormones to treat the symptoms of menopause, including hot flashes. It isn’t a good treatment for everyone, as it can be risky to those with conditions like coronary heart disease or a history of breast cancer, so talk with your doctor about your options.
For certain conditions, taking medication that treats the condition may also treat some of the symptoms related to it, so always consult your doctor if you think there’s something new going on with your body and you need relief.
