Sweating is (usually) normal: it’s your body’s way of controlling its temperature when it senses that it's starting to overheat. This is because sweat — which is mostly composed of water — encourages loss of heat through evaporation. Other causes of sweating include intense emotions such as anger and fear, spicy food, alcoholic drinks, menopause, and certain medications and illnesses.
Sweating can be unpleasant at the best of times, but it can be particularly uncomfortable during the night when you’re trying to rest. Night sweats are episodes of excessive perspiration that occur while you’re asleep.
If you’ve experienced night sweats before, you’re not alone — in a study of primary-care patients, 41% of participants reported having night sweats within the month they were surveyed.
Common causes of night sweats
There are a number of factors that can result in sweating at night, from the temperature of your bedroom to what you ate or drank before going to bed. Common causes include:
Having a comfortable sleep environment is essential to getting a good night’s rest. Your sleep environment may be causing you to sweat at night if you:
- Wear too many layers to bed
- Sleep in a bedroom that’s too warm
- Cover yourself with too much bedding
Sweating triggered by your sleep environment can be resolved by wearing fewer layers to bed, lowering the temperature of your bedroom, or adjusting the amount (or type) of bedding you use.
This kind of sweating is different from episodes of night sweats, which are not usually brought on by environmental aspects alone. Night sweats that persist despite changes to your sleep environment may be a sign of an underlying condition, and should be discussed with your doctor.
Anxiety and nightmares
There is a strong relationship between anxiety disorders and problems with sleep. Anxiety disorders can also manifest in physical symptoms — one of which is excessive sweating. Night sweats linked to anxiety may also be accompanied by:
- Feelings of dread, fear, or worry at night when you’re trying to fall asleep
- Feelings of irritability, tiredness, or weakness
- Problems falling asleep or staying asleep
- An upset stomach
- Unexplained aches or pains
- Tension in your muscles
In some instances, nightmares can lead to panic attacks, which often cause sweating. If you’re experiencing night sweats that you feel are related to an anxiety disorder, consult your healthcare provider for further guidance.
Your endocrine system regulates your body’s hormone levels. When the endocrine system undergoes changes, sometimes our bodies react by sweating.
As hormone levels fluctuate throughout the various stages of menopause, an individual may experience more hot flushes (or flashes) while they sleep. In fact, a 2007 study found that up to 80% of women going through menopause reported having night sweats or hot flashes.
Medical conditions such as overactivity of the thyroid (hyperthyroidism) and diabetes are also associated with night sweats — as are certain medications. For example, sweating at night can present as a side effect of hormone-blocking drugs and antidepressants.
Other parts of your body that interact with your endocrine system can be responsible for the onset of night sweats too. The hypothalamus — which is the part of your brain that’s responsible for controlling body temperature — is involved in maintaining the endocrine system. When the hypothalamus doesn’t function as it should, hormonal imbalances and sweating can occur.
Drinking alcohol affects the central nervous system, the circulatory system, and almost every part of your body. Alcohol consumption can increase your heart rate and widen blood vessels in your skin, which triggers sweating.
In some instances, alcohol intolerance can result in night sweats. Alcohol intolerance is a genetic mutation that prevents the body from producing enzymes that break down toxins in alcohol.
If you’re a regular drinker and you have night sweats — but you haven’t consumed alcohol recently — you may be experiencing alcohol withdrawal. Symptoms of alcohol withdrawal can appear as quickly as a few hours after your last drink or within several days. If your night sweats are correlated to alcohol withdrawal, your other symptoms may include:
- Feelings of anxiety, depression, tiredness, or irritability
- Nausea and/or fever
- Problems with sleep
- Loss of appetite
- Aches and pains
Regularly getting night sweats because of alcohol consumption can be an indicator of a drinking problem. If you feel your night sweats may be due to alcohol dependence, arrange an appointment with your doctor to discuss your concerns.
When to be concerned about night sweats
In general, night sweats that occur infrequently and don’t significantly impact sleep are not a cause for concern — but these episodes can still be uncomfortable. Aside from sleeping in a cooler environment, there are other steps you can take at home to address occasional or mild sweating at night:
- Limit consumption of caffeine and alcohol
- Try to maintain a healthy weight
- Avoid using drugs or tobacco
- Avoid eating spicy food if you are experiencing menopause, as this can aggravate symptoms
However — if your night sweats are accompanied by any of the following symptoms, you should consult your doctor:
- Unexplained weight loss
- Aches and pain
- Fever and chills
- Chronic or bloody cough
- Stomach pain or diarrhea
If you don’t have any of these symptoms but regularly experience night sweats that negatively impact your sleep, speak with your healthcare provider. A doctor can help determine whether an underlying condition is at the root of your problem and will be able to implement a suitable treatment plan if required.