Why Do I Sweat Excessively During Sleep? Insights from a Sleep Scientist

Reasons why we sweat during sleep and what can be done to prevent it

Why Do I Sweat Excessively During Sleep? Insights from a Sleep Scientist
It could be hot weather, hot flashes or illness, but certain periods of our lives are often punctuated by hot, sweaty and sleepless nights. But if you’re finding that you’re sweating more than normal without any discernible reason, you might be left wondering — why am I sweating so much in my sleep? While many of the best mattresses excel in temperature regulation, helping to keep you cool and comfortable all night long, some mattresses will trap heat, which can cause you to wake up in a pool of your own sweat. But beyond replacing your mattress, what are the other common causes of nighttime sweating? To coincide with Sleep Awareness Week 2024, we put that question to Theresa Schnorbach, a leading Sleep Expert at Emma, The Sleep Company. “Sweating in the night can have a number of causes,” says Dr Schnorbach. “Night sweats are a common menopausal symptom but can also be caused by some medicines or alcohol.” Let’s take a closer look at the common causes of night sweats, plus 5 things you can do to keep your cool at night.

Sweating is a natural and healthy body process that helps cool us down and remove toxins while we sleep. It’s normal to lose about 25ml of moisture per hour during sleep, which is why it’s important to use a good mattress protector.

On the other hand, night sweats are when you sweat so much that your bedding becomes soaked, waking you up and disrupting your sleep. There are specific health conditions and situations that can cause night sweats. They include:

Common reasons for sweating during sleep


Some medications like antidepressants, steroids, and certain cancer treatments can lead to night sweats. This is called drug-induced hyperhidrosis or excessive sweating.

Hormone fluctuations

Changes in hormones like estrogen and progesterone can lead to night sweats during the menstrual cycle, menopause, and pregnancy. Menopause, often called hot flashes, is one of the main causes of night sweats.

Stress and anxiety

Dr. Schnorbach explains that stress and anxiety can cause night sweats. This is because when we feel stressed or anxious, our body’s stress response, which includes a racing heart, can lead to more sweating while we sleep.

Alcohol consumption

Drinking alcohol, whether regularly, when stopping, or just one drink, can make you sweat more at night. Alcohol widens our blood vessels, leading to sweating. When you stop drinking alcohol, you might also experience increased night sweats as a withdrawal symptom.

Sleep apnea

Night sweats are a common symptom of sleep apnea, along with loud snoring and feeling tired despite getting enough sleep. This is because the body’s stress response that wakes people with sleep apnea to start breathing again also causes night sweats.


When you’re sick with a fever or infection, you might sweat more at night. This happens because when you’re ill, your body’s temperature rises, which can make your sweat glands more active. Sweating is your body’s way of staying cool when your temperature goes up.

5 ways to manage nighttime sweats

Dr. Schnorbach suggests five ways to control sweating at night, so we can stay cool and sleep better all night.

1. Cool your body’s pulse points

Dr. Schnorbach advises using ice packs wrapped in a cloth or towel (never directly on the skin) on pulse points like your wrists, temples, or neck sides to cool off quickly. You can also use a hot-water bottle filled with cold water or a cool, damp cloth on these areas. This cool sensation will help lower your core temperature. Avoid cooling your feet and hands too much, as this can make it harder to fall asleep.

2.  Wear lightweight pajamas

Dr. Schnorbach suggests wearing pajamas made of natural cotton if you prefer sleeping with clothes on. Cotton helps your skin breathe and absorbs sweat during the night.

3. Take a lukewarm shower

Dr. Schnorbach advises against taking a very cold shower before bed, even though it might seem like a good way to cool down. Instead, she suggests taking a lukewarm shower. A shower that is too cold can actually make your body warm up again to balance its temperature, which could make you sweat more.

 4. Evaluate your sleep environment

Dr. Schnorbach also recommends checking your sleep environment. A cooler bedroom can help lower your core body temperature, leading to deeper sleep. Opening a window can provide ventilation and cool air.
Studies indicate that the ideal sleep temperature is between 20 and 25 °C (68 and 77 F). However, since everyone is accustomed to different temperature settings, Dr. Schnorbach suggests setting your bedroom temperature to whatever feels comfortably cool to you, typically around 15-19°C (59°F – 66.2°F) for adults.

5. Invest in a cooling mattress

“Your bed and bedding could be contributing to night sweats,” says Dr. Schnorbach. “Thermoregulating layers in cooling mattresses can help redistribute body heat. Mattresses made from breathable materials allow more air to flow, enhancing this cooling effect.”

Night sweats are usually harmless but can be concerning if they regularly disrupt your sleep. Dr. Schnorbach suggests seeking advice from a doctor if this is the case. Adults need 7-9 hours of sleep for optimal function, so addressing the cause of night sweats is important if they are affecting your sleep.

“To sleep, our body’s core temperature needs to cool down, dropping by about 0.5°C [32.9°F] to fall asleep and another ~1°C [33.8°F] for deep sleep,” explains Dr. Schnorbach. “Night sweats can disrupt sleep, impacting both physical and mental health.”

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