Night Sweats: Common Causes and When to Worry

What night sweats usually mean

Night sweats are episodes of sweating that happen during sleep, often enough to dampen pajamas or sheets. They are different from simply feeling warm at night, because they can occur even in a cool room.

Sometimes the explanation is straightforward. Too many blankets, a warm bedroom, or breathable fabrics that trap heat can push your body past its comfort zone.

But night sweats can also be a clue that your body is responding to something, like a medication effect, a hormone shift, an infection, or inflammation.

Common reasons (starting with the most likely)

Your sleep environment and habits

Overheating is still the most common reason people sweat at night.

Room temperature, heavy bedding, and non-breathable sleepwear can all reduce your ability to cool down. Alcohol late in the evening can also widen blood vessels and disrupt sleep stages, which may make sweating more likely.

Spicy meals close to bedtime can trigger a temporary heat response in some people. So can a hot shower right before sleep if your body does not have time to cool down afterward.

Stress, anxiety, and sleep disruption

Strong emotions activate your sympathetic nervous system, the same “fight or flight” pathway that increases heart rate and sweating.

If you are waking up multiple times, having nightmares, or dealing with panic symptoms, you may notice sweating during or after those awakenings. This can create a loop, poor sleep increases stress hormones, which can further disrupt sleep.

Medications and substances

Several common medications list sweating as a side effect. Antidepressants are a frequent example, but other medicines can also affect temperature regulation.

Withdrawal from alcohol or certain sedatives can cause night sweats, especially in the first days to weeks after stopping. If your night sweats started soon after a new medication, a dose change, or stopping a medication, that timing matters.

Do not stop a prescribed medication on your own. A clinician can help you weigh risks, consider alternatives, or adjust timing and dose.

Hormone shifts and blood sugar swings

Hot flashes and night sweats are well known around perimenopause and menopause, but hormone-related sweating is not limited to midlife. Postpartum hormone changes and some thyroid conditions can also contribute.

Low blood sugar overnight can trigger sweating, shakiness, vivid dreams, or waking up hungry. This is more likely if you take insulin or other glucose-lowering medicines, but it can also occur with irregular meals, heavy evening exercise, or drinking alcohol without eating.

Pro Tip: If you suspect overnight blood sugar dips, avoid experimenting on your own. Track what is happening (timing, meals, exercise, alcohol) and bring it to your diabetes clinician or primary care provider for individualized guidance.

Autoimmune and inflammatory causes (why this niche matters)

Autoimmune conditions can raise your baseline inflammation, and inflammation can affect temperature regulation. Some people notice night sweats during a flare, when fatigue, pain, or low-grade fever are also present.

Night sweats can also show up when an autoimmune condition affects the endocrine system. For example, autoimmune thyroid disease can lead to too much thyroid hormone (hyperthyroid symptoms), which may cause heat intolerance, sweating, and a racing heart.

Immunosuppressing medications used for autoimmune disease can change infection risk. That matters because infections are a classic cause of night sweats, and they may be harder to spot if immune responses are blunted.

This does not mean night sweats automatically signal something serious. It does mean you should take a step back and look for patterns: Are the sweats new? Do they track with joint swelling, rashes, mouth ulcers, bowel symptoms, or medication changes?

Normal vs. worth checking

Occasional sweating that clearly relates to a warm room, a stressful week, or alcohol is usually not dangerous.

It is more worth checking if the sweats are “drenching,” frequent, or persistent, especially if you need to change clothes or sheets. New night sweats that continue for weeks deserve a conversation with a healthcare professional, even if you otherwise feel okay.

Important: Seek urgent care if night sweats occur with chest pain, trouble breathing, fainting, severe weakness, confusion, or signs of severe infection (such as high fever with shaking chills). If you have known heart disease, symptoms like chest pressure should be taken seriously, including in people with Coronary Artery Disease.

Other signs that should move night sweats higher on your “get checked” list include:

What often helps (practical steps)

Start with the simple fixes. They are low-risk and often effective.

If you have an autoimmune condition, also consider the bigger picture. A flare, a medication side effect, or an infection can look similar at first, and you may need labs or a medication review to sort it out.

Sunlight exposure and overall health habits can support immune and metabolic health, but they are not a substitute for evaluation when symptoms are persistent. If you are thinking about vitamin D, remember that Vitamin D Production varies widely by season, skin exposure, and geography, and testing may be more useful than guessing.

When to see a healthcare professional

Make an appointment if night sweats are new for you, happen repeatedly, or are affecting your sleep quality.

It can help to bring a short symptom log for 1 to 2 weeks. Include when the sweating happens, room temperature and bedding, alcohol intake, exercise timing, menstrual cycle timing (if relevant), and any other symptoms like fever, cough, pain, or weight changes.

If you live with an autoimmune disease or take immune-suppressing medicines, contact your clinician sooner rather than later. The threshold for checking infection and medication effects is typically lower in this group.

If you are worried, it is reasonable to ask what evaluation makes sense for you. Clinicians often start with a history and exam, a medication review, and basic blood tests guided by your symptoms, and then tailor next steps from there.