What causes night sweats?

Jonathan Warren

Author: Jonathan Warren



What causes night sweats?

Night sweats are an unpleasant and potentially disruptive occurrence that can affect lots of different people. We’re going to look at the symptoms, possible causes and some ways of managing the symptoms in this article. 

What are the symptoms of night sweats? 

  • Drenching perspiration during sleep
  • Waking up with soaked pyjamas or sheets
  • Disrupted sleep patterns
  • Chills following sweating episodes
  • Fatigue and irritability due to sleep disturbances

Possible causes of night sweats 

Autoimmune disorders

Night sweats could be an indicator of an autoimmune disorder, such as rheumatoid arthritis, multiple sclerosis, celiac disease, and lupus. One of the body’s first defence against disease is to raise its temperature to eliminate the threat, but for those suffering from autoimmune disorders, their bodies mistake healthy cells as threats which triggers the same reaction. 


If you’re struggling with depression or anxiety, your body experiences a stress response. During this, your brain releases hormones including cortisol and adrenaline which can cause stress sweat and unfortunately, this reaction can occur even while you’re sleeping. 

Medication side effects

If you’ve recently started a new medication, it is possible that you might experience night sweats as a side effect. Check through the information provided by your doctor and if you have any concerns reach out to them for more advice. 

Infections or illnesses 

Similarly to how autoimmune disorders trigger a temperature rise, for anyone who’s contracted an infection or illness, their body is likely to create a fever to fight this off. Night sweats are especially challenging for those who are struggling with illness as rest is crucial for recovery. If symptoms persist for longer than expected, it is a good idea to visit your doctor.

Hormone changes

Similar to hot flashes, night sweats can be triggered by hormone changes which make it harder for your brain to regulate your body temperature. They are especially common during menopause, perimenopause, pregnancy and at certain points during the menstrual cycle. 

An overactive thyroid

Also known as hyperthyroidism, those suffering from an overactive thyroid gland are likely to experience difficult symptoms. The thyroid gland produces thyroid hormone which is responsible for regulating lots of bodily functions, affecting metabolism, development, and crucially temperature regulation. This means that night sweats are a common symptom, which could be due to difficulty regulating temperature, especially in situations where individuals might be wearing thick pyjamas or sleeping under thick duvets. 

Alcohol consumption 

Alcohol impacts your nervous system, causing a fluctuation in blood pressure, heart rate, and body temperature. Sweating after alcohol consumption could indicate an intolerance or withdrawal so it’s a good idea to seek medical help if you do experience night sweats consistently after consuming alcohol. 


Excessive sweating is common and it can affect some areas or the whole body. It is normal to sweat if you’re doing exercise or if you’re somewhere hot but its possible you’re experiencing hyperhidrosis if you’re sweating even when you don’t need to cool down. If this is something you’re suffering from, try to wear moisture-wicking clothing and choose breathable bedding. 

How to manage night sweats

  1. Determine why you’re experiencing night sweats 
  2. Keep your bedroom as cool as possible 
  3. Adjust your diet, reducing caffeine, spicy food and alcohol intake 
  4. Manage your stress as much as possible 
  5. Keep hydrated 
  6. Speak to your doctor if they persist 

This is not an exhaustive list of possible night sweats causes and while some may sound alarming, there are lots of innocent reasons for night sweats. If you’re experiencing night sweats then it is likely your body is trying to tell you something is wrong. The best thing to do if you’re experiencing them is to speak to your doctor. 

Night sweats can be a confusing and unpleasant thing to deal with as they can lead to disrupted sleep but they aren’t always something to worry about. If you’ve been experiencing night sweats on multiple occasions and you have other symptoms such as weight loss or a fever then you should speak to your doctor immediately. 

Want more tips to help with your sleep hygiene journey? 

We’ve got you covered. Our Time4Sleep blog has a number of helpful resources and tips to help you get the most of your sleep.