Cold sweats at night happen when your body produces excessive sweat that isn’t triggered by a hot room or heavy blankets. Unlike regular sweating from overheating, cold sweats involve a physiological response from an underlying cause, whether that’s hormonal shifts, blood sugar drops, anxiety, medication, or something else entirely. The cause ranges from completely benign to worth investigating, and the pattern of your symptoms is what separates one from the other.
What Makes Cold Sweats Different From Regular Sweating
When you overheat, your body sweats to cool down. Cold sweats work differently. Your skin feels clammy and damp, but you’re not hot. Sometimes you feel chilled at the same time. This happens because your nervous system is activating sweat glands in response to an internal signal: a hormone fluctuation, a stress response, a drop in blood sugar, or an immune reaction. The sweat itself is real, but the trigger is coming from inside your body rather than from your environment.
Doctors use the term “diaphoresis” for excessive sweating caused by an underlying condition rather than external heat or exercise. Cold, clammy skin alongside this kind of sweating can sometimes signal something serious, but far more often it points to one of several common and manageable causes.
Hormonal Changes During Perimenopause and Menopause
If you’re a woman in your 40s or 50s, hormonal shifts are the most likely explanation. Between 60% and 80% of women experience hot flashes or night sweats at some point during the menopausal transition, according to data from the Study of Women’s Health Across the Nation (SWAN). These episodes peak in the years immediately surrounding your final menstrual period.
What happens is straightforward: declining estrogen and rising levels of follicle-stimulating hormone send false signals to your brain’s temperature-regulation center, essentially tricking it into thinking you’re overheating. Your body responds with a sudden wave of heat, flushing, and sweating, concentrated around the head, neck, chest, and upper back. At night, this can soak your sheets and leave you shivering afterward as the sweat evaporates.
A sizable number of women report these symptoms earlier than expected, before noticeable changes to their menstrual cycle, and some continue experiencing them well into their 60s and 70s. So even if you don’t think you’re “in menopause,” hormonal changes could still be driving your night sweats. Women with anovulatory cycles (months where no egg is released) are particularly likely to experience them.
Low Blood Sugar While You Sleep
Nocturnal hypoglycemia occurs when blood glucose falls below 70 mg/dL during sleep. It’s most common in people with diabetes who take insulin or certain oral medications, but it can also happen if you skipped dinner, drank alcohol in the evening, or exercised intensely late in the day. Your body treats low blood sugar as an emergency and floods your system with stress hormones, producing hot, clammy, sweaty skin along with shakiness, a racing heart, or vivid nightmares.
If you wake up drenched and also feel confused, shaky, or unusually hungry, blood sugar is worth checking. People with diabetes who notice a pattern should talk to their care team about adjusting their evening medication or adding a bedtime snack with protein and complex carbohydrates.
Anxiety and Nocturnal Panic Attacks
Your fight-or-flight system doesn’t shut off just because you’re asleep. Nocturnal panic attacks can jolt you awake with profuse sweating, a racing heart, chest tightness, trembling, and an intense feeling of terror. These episodes happen because something in the way your brain processes fear and anxiety misfires during sleep, triggering the same cascade of stress hormones you’d experience during a daytime panic attack.
If you’re going through a stressful period, dealing with generalized anxiety, or have a history of panic disorder, this is a common culprit. The sweating itself isn’t dangerous, but the combination of waking up drenched and terrified can severely disrupt your sleep quality and feed a cycle of anxiety about going to bed.
Sleep Apnea
This one surprises most people. Obstructive sleep apnea, where your airway repeatedly collapses during sleep, is strongly linked to night sweats. About 31% of men and 33% of women with sleep apnea report frequent nocturnal sweating (three or more times per week), compared to roughly 9% to 12% of the general population. The repeated drops in oxygen and spikes in effort to breathe activate your stress response, which triggers sweating.
The connection is strong enough that treating sleep apnea with a CPAP machine has been shown to reduce both sweating and elevated blood pressure. If your night sweats come alongside snoring, daytime exhaustion, or a partner telling you that you stop breathing in your sleep, sleep apnea deserves a closer look.
Medications That Cause Night Sweats
Several common medications list night sweats as a side effect, and antidepressants are among the most frequent offenders. In one study of older adults in primary care, about 22.5% of patients taking SSRIs (a widely prescribed class of antidepressants) reported night sweats, roughly three times the rate of those not taking them. Other medications commonly associated with nocturnal sweating include other types of antidepressants, blood pressure drugs, hormone therapies, and some over-the-counter fever reducers like aspirin or acetaminophen taken at bedtime.
If your night sweats started around the same time as a new prescription or dosage change, that timing is worth noting. Don’t stop a medication on your own, but bringing this pattern to your prescriber can open the door to adjusting the dose or switching to an alternative.
Infections and Immune Responses
Your immune system ramps up activity at night, which is why fevers often spike after dark and why infections commonly produce nighttime sweating. The most well-known example is tuberculosis, where sweating at night is considered a hallmark symptom alongside fever, weight loss, fatigue, and persistent cough. But many other infections can cause it too, including bacterial infections like endocarditis, viral illnesses, and fungal infections.
Infection-related night sweats typically come with other obvious signs that you’re sick: fever during the day, fatigue, loss of appetite, or pain. If you’re otherwise feeling fine, an active infection is less likely to be the explanation.
When Night Sweats Signal Something More Serious
Lymphoma and certain other cancers can cause what doctors describe as “drenching” night sweats, the kind where you need to change your sheets and clothing. In the context of lymphoma, these are defined as recurrent and drenching over the course of a month, and they’re typically accompanied by unexplained weight loss and persistent fevers. It’s worth knowing that no study has established how reliably drenching night sweats alone predict cancer versus a benign cause, so the presence of additional symptoms matters a great deal.
Night sweats that occur regularly, interrupt your sleep, or come alongside unexplained weight loss, fever, a persistent cough, localized pain, or diarrhea warrant a medical evaluation. The same applies if you went through menopause years ago and night sweats have returned after a long gap.
Practical Steps to Reduce Night Sweats
While you work on identifying the underlying cause, your sleep environment plays a significant role. Keep your bedroom between 65 and 68 degrees Fahrenheit, which is the range most conducive to restful sleep. Switch to breathable bedding and sleepwear made from cotton, linen, or bamboo rather than synthetic fabrics that trap heat and moisture. A lighter blanket you can easily push off helps you respond quickly when a sweat episode starts.
Beyond your bedroom setup, a few habits can make a difference. Avoid alcohol, spicy food, and caffeine in the evening, all of which can trigger or worsen sweating. If blood sugar might be a factor, a small protein-rich snack before bed can stabilize glucose levels overnight. Keeping a brief log of when the sweats happen, what you ate and drank, and any other symptoms you noticed gives you (and your doctor, if you end up going) a much clearer picture of what’s driving the problem.