Night sweats in men are most often caused by medications, low testosterone, sleep apnea, alcohol use, or infections. Between 10% and 41% of adults experience night sweats, and while the cause is usually something treatable or lifestyle-related, persistent drenching sweats can occasionally signal a more serious condition.
True night sweats are different from simply feeling warm because your bedroom is stuffy or you piled on too many blankets. They involve sweating heavy enough to soak through your clothes or sheets, even in a cool room. If that’s happening to you regularly, the list of possible explanations is worth walking through carefully.
Low Testosterone and Thermoregulation
Declining testosterone is one of the most common hormonal causes of night sweats in men. Testosterone levels naturally drop with age, roughly 1% per year after 30, but certain medical conditions, medications, or treatments (like androgen deprivation therapy for prostate cancer) can cause a sharper decline. The result is essentially the male equivalent of hot flashes.
The mechanism works like this: low testosterone disrupts the brain’s temperature control center, the hypothalamus. When it misreads your body temperature, the nervous system sends signals that widen blood vessels in the skin, producing a sudden flush of warmth. Your body then overcorrects by triggering a cold, clammy sweat. This cycle can happen multiple times per night, pulling you out of deep sleep and leaving sheets damp.
An overactive thyroid can produce a similar effect. Excess thyroid hormone raises your baseline metabolic rate, generating more body heat than your cooling system can handle quietly. Both conditions are easily detected with blood work.
Medications That Trigger Sweating
A surprisingly long list of common medications can cause night sweats as a side effect. If your sweating started around the same time you began a new prescription, that’s worth investigating. The most frequently implicated drug classes include:
- Antidepressants, particularly SSRIs and tricyclic antidepressants, are among the most common medication causes of night sweats.
- Blood pressure medications, including beta blockers and angiotensin II receptor blockers.
- Diabetes medications, including insulin and oral blood sugar-lowering drugs, which can trigger sweating when blood sugar drops too low overnight.
- Hormone-related drugs, such as testosterone therapy, antiandrogens, and thyroid supplements.
- Over-the-counter drugs, including NSAIDs (like ibuprofen), antihistamines, and decongestants.
- Corticosteroids, such as prednisone.
If you suspect a medication is the cause, don’t stop taking it on your own. Your doctor can often adjust the dose or switch to an alternative that doesn’t have the same effect.
Sleep Apnea
Obstructive sleep apnea, a condition where your airway repeatedly collapses during sleep, is strongly linked to night sweats in men. Roughly 30% of people with sleep apnea report night sweats, compared to about 12% of people without the condition.
The connection appears to involve drops in blood oxygen levels. Each time your airway closes, your body goes through a mini stress response: your heart rate spikes, stress hormones surge, and your nervous system activates the same fight-or-flight pathways that trigger sweating. If you snore heavily, wake up gasping, or feel exhausted despite a full night of sleep, sleep apnea is a likely contributor. Treating the apnea, typically with a CPAP device, often resolves the sweating as well.
Alcohol and Substance Use
Alcohol is a direct cause of night sweats, even in moderate amounts. Drinking raises your heart rate and widens blood vessels in the skin, which increases heat loss and triggers perspiration. A few drinks in the evening can be enough to produce noticeable sweating a few hours later as your body metabolizes the alcohol.
The effect is more intense for heavy or regular drinkers. If your body has become physically dependent on alcohol, skipping a night or cutting back can cause withdrawal sweating, sometimes severe. In its most extreme form, alcohol withdrawal produces a dangerous condition called delirium tremens, which involves drenching sweats, fever, hallucinations, and seizures. Even milder withdrawal commonly causes clammy skin and night sweats within hours of the last drink.
Recreational drugs and caffeine consumed late in the day can also contribute, though alcohol is by far the most common substance-related cause.
Infections
Chronic and acute infections are a classic cause of night sweats, sometimes the first noticeable symptom. Tuberculosis is the most well-known example, but bacterial infections like endocarditis (an infection of the heart valves), abscesses, and bone infections can all produce drenching nighttime sweating. HIV is another infection strongly associated with night sweats, particularly in earlier stages before diagnosis.
The pattern with infections tends to be distinctive. The sweating is usually accompanied by fever, unexplained weight loss, or general fatigue. If you’re experiencing night sweats alongside any of these symptoms, especially after travel or potential exposure, infection should be high on the list of possibilities.
Lymphoma and Other Cancers
Night sweats are one of the hallmark “B symptoms” of lymphoma, a group of cancers that affect the immune system. The other two B symptoms are unexplained fever and unintentional weight loss of more than 10% of body weight. This triad applies to both Hodgkin and some non-Hodgkin lymphomas.
The sweating associated with lymphoma is typically severe: drenching enough that you need to change your bedclothes. It’s not the kind of mild dampness you might notice on a warm night. Other cancers, including leukemia and certain solid tumors, can also cause night sweats, though less characteristically than lymphoma.
Cancer is a far less common cause of night sweats than medications, hormones, or sleep apnea. But if your sweats are persistent, severe, and accompanied by weight loss, fevers, or swollen lymph nodes, those are the red flags that prompt doctors to investigate further.
Anxiety and Stress
Chronic anxiety and high stress levels activate the sympathetic nervous system, the same fight-or-flight system that controls sweating. For some men, this activation continues during sleep, producing night sweats even without a diagnosable medical condition. Nightmares and PTSD-related sleep disturbances can trigger the same response.
Stress-related night sweats tend to come and go with life circumstances rather than persisting every single night. They’re also more likely to be accompanied by difficulty falling asleep, racing thoughts, or waking with a pounding heart. If this pattern sounds familiar, treating the underlying anxiety often resolves the sweating.
What Patterns to Pay Attention To
Not all night sweats need medical evaluation. If you can trace the sweating to a warm bedroom, heavy blankets, spicy food before bed, or a night of drinking, the cause is straightforward. The sweating that deserves attention is the kind that happens repeatedly in a cool environment with no obvious trigger.
Keep track of a few details before bringing it up with your doctor: how many nights per week it happens, whether the sweating is severe enough to soak through clothing or sheets, and whether you’ve noticed any accompanying symptoms like weight changes, fevers, fatigue, or new medications. These details help narrow the list quickly. In most cases, the evaluation involves blood work to check hormone levels, thyroid function, blood sugar, and markers of infection or inflammation. If sleep apnea is suspected, a sleep study is the standard next step.
The majority of men with night sweats have a cause that is identifiable and treatable. Medication adjustments, hormone therapy, CPAP for sleep apnea, or simply cutting back on alcohol resolve the problem for most people once the underlying trigger is found.