Night sweats in men have a wide range of causes, from a bedroom that’s simply too warm to hormonal shifts, medications, sleep disorders, and occasionally something more serious. The good news: most men who bring up persistent night sweats with their doctor do not have a dangerous underlying condition. But understanding the possible reasons can help you figure out whether your sweating is worth investigating further.
Low Testosterone and Hormonal Shifts
Testosterone levels naturally decline as men age, typically dropping about 1% per year after age 30. When levels fall low enough, the body’s internal thermostat, located in a brain region called the hypothalamus, can start misfiring. The nervous system sends signals that widen blood vessels in the skin, producing a sudden flush of warmth. To cool itself back down, the body rapidly converts that flush into a cold, clammy sweat. The result feels a lot like the hot flashes women experience during menopause.
This isn’t limited to older men. Testosterone can drop for other reasons too: chronic stress, obesity, certain medications, or medical treatments. Men undergoing hormone therapy for prostate cancer are especially prone to these episodes. If your night sweats come with other low-testosterone symptoms like fatigue, reduced sex drive, or difficulty concentrating, a simple blood test can check your levels.
Sleep Apnea
Obstructive sleep apnea, where your airway repeatedly collapses during sleep, is one of the most overlooked causes of night sweats in men. A study published in the European Respiratory Journal found that 31% of people with sleep apnea reported frequent night sweats (three or more times per week), compared to just 11% of the general population. The repeated oxygen drops and surges of stress hormones that come with each breathing pause push the body into a fight-or-flight state throughout the night, which drives sweating.
If you snore loudly, wake up gasping, or feel exhausted despite a full night’s sleep, sleep apnea is worth considering. Treating it often resolves the sweating along with the other symptoms.
Alcohol and Diet
Drinking alcohol, especially in the evening, is one of the most common and most easily fixable triggers. Alcohol affects the central nervous system and circulatory system simultaneously. It increases heart rate and widens blood vessels in the skin, which triggers perspiration. Even moderate drinking can disrupt your body’s ability to regulate temperature during sleep, and the effect is stronger the closer you drink to bedtime.
Spicy food, caffeine, and large meals eaten late at night can have a similar, though usually milder, effect. Your body generates heat during digestion, and certain compounds in spicy food directly activate heat receptors. If your night sweats tend to follow specific meals or drinks, the connection may be straightforward.
Medications That Cause Sweating
Several common medications list excessive sweating as a side effect. Antidepressants, particularly SSRIs like sertraline, fluoxetine, and citalopram, are among the most frequent culprits. These drugs influence serotonin levels, which in turn affect the hypothalamus and spinal cord pathways that control sweating. Steroid medications like prednisone can also trigger sweating by disrupting hormonal feedback loops that regulate body temperature.
Other categories include blood pressure medications, diabetes drugs (which can cause low blood sugar overnight, prompting sweats), and some over-the-counter fever reducers. If your night sweats started around the same time you began a new medication, that timing is worth noting and bringing up with your prescriber. Switching to a different drug in the same class often solves the problem.
Infections and Immune Responses
Your body raises its temperature to fight off infections, and sweating is part of how it brings that temperature back down. Short-term illnesses like the flu or a cold can cause a few nights of sweating that resolves on its own. More persistent night sweats, lasting weeks, can point to chronic infections. Tuberculosis is the classic example and has been associated with drenching night sweats for centuries. HIV, mononucleosis (caused by the Epstein-Barr virus), heart valve infections (endocarditis), and pneumonia can all produce ongoing night sweats as well.
These infections typically come with other symptoms: fever, chills, unexplained weight loss, persistent cough, or swollen lymph nodes. Night sweats alone, without any of those accompanying signs, are unlikely to indicate a serious infection.
Cancer and Lymphoma
This is the possibility that drives most people to search in the first place, so it’s worth addressing directly. Lymphoma (both Hodgkin and non-Hodgkin types) and leukemia are the cancers most strongly associated with night sweats. In lymphoma specifically, the combination of fever, drenching night sweats, and unexplained weight loss is considered a significant warning pattern.
Context matters here. Cancer-related night sweats tend to be severe, soaking through clothes and sheets, and they persist night after night. They almost always appear alongside other symptoms: swollen lymph nodes you can feel in your neck, armpits, or groin; unexplained weight loss of 10% or more of your body weight; or recurrent fevers without an obvious cause. If you’re sweating at night but otherwise feel healthy, cancer is far down the list of likely explanations.
Overactive Thyroid
Your thyroid gland controls your metabolic rate. When it’s overactive (hyperthyroidism), your body essentially runs hotter than it should, producing excess heat around the clock. At night, this extra heat has nowhere to go, and sweating is the body’s main cooling mechanism. Other signs of an overactive thyroid include unexplained weight loss despite a normal or increased appetite, a rapid or irregular heartbeat, trembling hands, and feeling anxious or wired for no clear reason. A blood test measuring thyroid hormone levels can confirm or rule this out quickly.
Your Sleep Environment
Before looking for medical explanations, it’s worth ruling out the obvious. A room temperature above 65 to 68°F (18 to 20°C) can be enough to trigger sweating during sleep, especially if you’re under heavy blankets or wearing synthetic fabrics that trap heat. Memory foam mattresses retain more body heat than innerspring or latex options. Even sharing a bed with a partner or pet raises the ambient temperature around you.
Switching to breathable cotton or moisture-wicking sheets, lowering the thermostat, and sleeping in lighter clothing are simple first steps. If those changes eliminate the sweating, you likely have your answer.
Patterns Worth Paying Attention To
Occasional night sweats on a hot evening or after a night of drinking are rarely cause for concern. The sweats that warrant a closer look share a few features: they happen regularly (several times per week), they’re severe enough to soak your sheets or pajamas, and they don’t have an obvious environmental explanation. Pay particular attention if they come alongside unexplained weight loss, persistent fevers, swollen glands, or new fatigue that doesn’t improve with rest. That combination of symptoms, not night sweats alone, is what signals something that needs evaluation.
Keeping a brief log of when the sweats happen, what you ate or drank that evening, and any accompanying symptoms can make the conversation with your doctor much more productive. In many cases, the cause turns out to be something manageable, like adjusting a medication, treating sleep apnea, or checking hormone levels.