Night sweats in men are common, and most of the time they trace back to something fixable: a warm bedroom, alcohol before bed, or stress. But when sweating is heavy enough to soak through your clothes or sheets on a regular basis, it can signal something worth investigating, from low testosterone to sleep apnea to less common but serious conditions like infections or lymphoma.
The distinction matters. Waking up a little damp because your comforter is too thick is not the same as true night sweats. The Mayo Clinic defines night sweats as repeated episodes of very heavy sweating during sleep, heavy enough to soak your nightclothes or bedding, regardless of how warm the room is.
How Your Body Regulates Temperature at Night
Your body temperature naturally drops as you fall asleep, reaching its lowest point in the early morning hours. This cooling process is managed by the hypothalamus, a small region of the brain that acts as your internal thermostat. When something disrupts that thermostat, the hypothalamus can misread signals and trigger a cooling response you don’t need. Blood vessels near the skin widen, producing a sudden flush of warmth. Your body then overcorrects by sweating heavily to bring the temperature back down. That rapid swing from hot flush to cold, clammy sweat is the basic mechanism behind most night sweats, regardless of the underlying cause.
Low Testosterone
Testosterone levels in men begin declining gradually after age 30, typically dropping about 1% per year. When levels fall low enough, the hypothalamus becomes less stable in how it reads and regulates body temperature. The result is similar to hot flashes in menopausal women: sudden vasodilation (blood vessels opening up near the skin), a wave of heat, and then sweating to compensate.
Low testosterone night sweats tend to come with other symptoms: fatigue, reduced sex drive, difficulty concentrating, and changes in mood. If those sound familiar alongside your night sweats, a blood test measuring your testosterone level can confirm or rule it out. Men undergoing androgen deprivation therapy for prostate cancer experience this effect more dramatically, but naturally declining testosterone can produce it too.
Sleep Apnea
Obstructive sleep apnea is one of the most underrecognized causes of night sweats in men. Research published in the European Respiratory Journal found that 31% of people with obstructive sleep apnea reported frequent night sweats (three or more times per week), compared to just 11% of the general population. That’s nearly a threefold increase.
Sleep apnea causes your airway to collapse repeatedly during sleep, which forces your body into a stress response each time breathing stops. Your heart rate and blood pressure spike, stress hormones surge, and your nervous system ramps up, all of which generate heat. If you snore loudly, wake up gasping, or feel exhausted despite a full night of sleep, apnea may be driving your sweating. Many men don’t realize they have it until a partner notices the snoring or breathing pauses.
Alcohol, Caffeine, and Spicy Food
Alcohol is one of the most common triggers for nighttime sweating in men. It widens blood vessels near the skin, which releases heat and can trigger a sweat response as you metabolize it during sleep. Even moderate drinking, two or three drinks in the evening, can be enough to cause noticeable sweating a few hours later.
Caffeine works differently but lands in a similar place. It suppresses melatonin, the hormone that helps your body cool down for sleep, and keeps your core temperature elevated. Research has shown that 200 mg of caffeine (roughly two cups of coffee) significantly blunts the normal nighttime drop in body temperature. If you’re drinking coffee or energy drinks in the afternoon or evening, that alone could explain your sweating. Spicy food also raises core temperature and can provoke sweating, especially within a few hours of bedtime.
Medications That Cause Night Sweats
A surprising number of common medications list night sweats as a side effect. Antidepressants, particularly SSRIs and SNRIs, are among the most frequent culprits. Other categories include:
- Blood pressure medications that alter how your blood vessels regulate heat
- Blood sugar medications that can cause low blood sugar overnight, triggering a sweat response
- Hormone therapies used for prostate conditions
- Over-the-counter fever reducers like aspirin or acetaminophen, which can cause rebound sweating as they wear off
If your night sweats started around the same time as a new medication, that timing is worth noting. Don’t stop taking a prescribed medication on your own, but it’s a conversation worth having with your prescriber.
Infections and Serious Conditions
Night sweats that are persistent, drenching, and accompanied by other symptoms can occasionally point to something more serious. The conditions most strongly associated with night sweats include:
Tuberculosis typically presents with a cough along with weight loss and low-grade fever. Many patients experience night sweats several times per week. While TB rates are low in many countries, it remains a consideration, especially if you’ve traveled to or lived in areas where it’s more common.
Hodgkin’s lymphoma frequently causes low-grade fever paired with night sweats. In some cases, high fluctuating fevers with drenching sweats can persist for weeks. Non-Hodgkin’s lymphoma can also cause sweating, though less consistently. Enlarged lymph nodes that feel firm and painless, particularly in the neck or armpits, are a hallmark sign.
HIV infection commonly causes fever with or without night sweats, either from the virus itself or from related infections. Infectious endocarditis, an infection of the heart valves, also produces sweating alongside fatigue, chills, and fever.
These conditions are far less common than the lifestyle and hormonal causes above, but they’re the reason persistent night sweats deserve attention rather than dismissal.
Red Flags Worth Taking Seriously
Not every episode of nighttime sweating needs medical workup. But certain combinations of symptoms raise the stakes significantly. The signs that should prompt a visit to your doctor include:
- Unintentional weight loss of more than 5% of your body weight over six to twelve months
- Persistent fever that you can measure with a thermometer, not just feeling warm
- Swollen lymph nodes in your neck, armpits, or groin that persist for more than four to six weeks
- Night sweats that happen multiple times per week for several weeks without an obvious explanation
Any of these alongside night sweats signals that your body may be fighting something that needs investigation. Weight loss, fever, and lymph node changes in particular are the trio that clinicians use to flag higher-risk cases for infection or malignancy screening.
Practical Ways to Reduce Night Sweats
If your night sweats are mild to moderate and you don’t have any red flag symptoms, adjusting your sleep environment and habits can make a real difference. Keep your bedroom cool. Running an air conditioner, ceiling fan, or oscillating fan near the bed all help. There’s no single magic number for room temperature, but most sleep experts suggest somewhere around 65 to 68°F (18 to 20°C).
Your bedding matters too. Cotton and linen sheets breathe well and release heat. Moisture-wicking fabrics, originally designed for athletic wear, are now available in pajamas and sheets and work well for some people. Avoid synthetic materials that trap heat against your skin.
On the habit side, cutting off alcohol three to four hours before bed and moving your last caffeine intake to before noon are two of the simplest changes with the biggest payoff. If you exercise in the evening, try shifting your workout earlier in the day. Intense exercise raises your core temperature for several hours afterward, and that residual heat can spill into your sleep.
For night sweats driven by low testosterone, sleep apnea, or medication side effects, the environmental fixes above can take the edge off, but addressing the underlying cause is what ultimately resolves the problem. A sleep study can diagnose apnea. A blood draw can check your testosterone and thyroid levels. And a medication review with your prescriber can identify whether a drug switch might help.