Night sweats affect a large portion of the general population and range from mildly annoying to a sign of something worth investigating. In most cases, the cause is something fixable: a warm bedroom, the wrong bedding, alcohol before bed, or a medication side effect. But persistent, drenching sweats that soak your sheets can sometimes point to hormonal changes, sleep apnea, infections, or other medical conditions that benefit from treatment.
Your Bedroom Might Be Too Warm
The simplest explanation is often the right one. Your body naturally drops its core temperature during sleep, and if your environment fights that process, you sweat. The ideal bedroom temperature for sleep is between 60 and 67°F (15 to 19°C), which feels cooler than most people expect. If your thermostat is set to 72°F or higher, that alone could explain why you’re waking up damp.
Heavy blankets, memory foam mattresses (which trap heat), and synthetic sheets all make the problem worse. Breathable materials like cotton, linen, and bamboo-derived fabrics wick moisture away from your skin and let heat escape. Linen is particularly effective for hot sleepers. If you prefer the smooth feel of traditional sheets, look for a percale weave rather than sateen, which tends to trap more heat. Tencel, made from eucalyptus fiber, is another strong option for moisture management, especially in humid climates.
Alcohol, Food, and Caffeine Before Bed
What you consume in the hours before sleep has a direct effect on your body temperature overnight. Alcohol increases your heart rate and widens blood vessels in your skin, which triggers perspiration. Even a couple of drinks with dinner can be enough to cause noticeable sweating later that night. The effect is more pronounced with heavier drinking, but it doesn’t take much.
Spicy foods and caffeine can also raise your core temperature or stimulate your nervous system enough to interfere with your body’s normal cooling process. A high-fat, high-sugar diet has been linked to increased night sweats as well, particularly in women approaching menopause. If your sweating tends to be worse on certain nights, tracking what you ate and drank that evening can reveal a pattern surprisingly quickly.
Medications That Cause Night Sweats
Several common medications list night sweats as a side effect. Antidepressants, particularly SSRIs, are among the most frequent culprits. Other drug classes associated with nighttime sweating include hormone therapy, blood pressure medications (specifically angiotensin II receptor blockers), corticosteroids, thyroid hormone supplements, and diabetes medications that lower blood sugar. If your night sweats started around the same time you began a new medication, that timing is worth mentioning to whoever prescribed it. In many cases, adjusting the dose or switching to a different medication resolves the problem.
Hormonal Changes and Menopause
For women in their 40s and 50s, hormonal shifts are the most likely explanation. Hot flashes and night sweats occur in up to 80% of women during menopause, and they last an average of 7 to 10 years. Each episode typically runs 1 to 5 minutes and often comes with a sudden wave of heat, sweating, chills afterward, and sometimes anxiety. These episodes can happen multiple times per night, severely disrupting sleep quality.
Night sweats from menopause are caused by fluctuating estrogen levels, which interfere with the part of your brain that regulates temperature. Your body essentially misreads its own thermostat and launches a cooling response (sweating) when none is needed. Perimenopause, the transitional years before periods fully stop, can trigger the same symptoms. Hormonal night sweats aren’t limited to menopause, though. Thyroid disorders, particularly an overactive thyroid, can produce similar effects in anyone.
Sleep Apnea and Breathing Problems
Obstructive sleep apnea, a condition where your airway repeatedly closes during sleep, is an underrecognized cause of night sweats. When your airway collapses, your oxygen levels drop and your body mounts a stress response that includes sweating, elevated blood pressure, and a surge in heart rate. Many people with sleep apnea don’t realize they have it because the breathing interruptions happen while they’re asleep. The clues are often indirect: loud snoring, waking up feeling unrested, morning headaches, and yes, unexplained sweating.
Research from the Icelandic Sleep Apnea Cohort found that treating sleep apnea with a breathing device reduced both sweating and blood pressure. If you sweat heavily at night and also snore or feel exhausted despite getting enough hours of sleep, sleep apnea is worth investigating.
Anxiety, Depression, and Stress
Your mental health has a direct line to your sweat glands. Panic attacks can occur during sleep, producing sudden sweating along with a racing heart and a feeling of dread. Depression, post-traumatic stress disorder, and chronic anxiety are all independently associated with night sweats. Stress hormones activate your sympathetic nervous system, the same system responsible for your fight-or-flight response, and that activation triggers perspiration even while you’re unconscious. If you’re dealing with significant stress or a mental health condition, nighttime sweating may improve as the underlying issue is addressed.
Infections and Immune Conditions
Night sweats are a classic symptom of certain infections. Tuberculosis is the most well-known example, but bacterial infections of the heart valves (endocarditis), bone infections, and abscesses can all cause drenching sweats. Infectious mononucleosis and HIV are also associated with this symptom. Autoimmune conditions like sarcoidosis and giant cell arteritis can produce night sweats as well. In these cases, sweating is usually accompanied by other symptoms like fever, fatigue, or unexplained weight loss.
When Night Sweats Signal Something Serious
Most night sweats are not dangerous. But certain patterns warrant prompt attention. Drenching sweats that soak through your clothes and bedding, especially when combined with unexplained weight loss, persistent fever, unusual lumps or swelling, or unexplained pain, can be associated with lymphoma and other cancers. These are sometimes called “B symptoms” in the context of blood cancers.
The key distinction is between occasional sweating on a warm night after a glass of wine and persistent, heavy sweating that happens regularly regardless of your environment. If you’ve already addressed the obvious factors (room temperature, bedding, alcohol, medications) and you’re still waking up soaked, or if you’re also losing weight without trying, running fevers, or feeling unusually fatigued, those are signs that something beyond your sleep environment needs attention.
Practical Steps to Reduce Night Sweats
Start with the factors you can control. Keep your bedroom between 60 and 67°F. Switch to breathable bedding: linen, cotton with a percale weave, or bamboo-derived fabric. Avoid alcohol, spicy food, and caffeine in the 2 to 3 hours before bed. Wear lightweight, moisture-wicking sleepwear or sleep without heavy clothing.
If those changes don’t help, review your medications for known links to sweating. Consider whether you have other symptoms that point to a hormonal issue, sleep apnea, or an anxiety disorder. Keeping a simple log of when sweating occurs, how severe it is, and what you ate, drank, or took that day can help you and your doctor identify the cause faster than any single test.