Why you drool when sleeping and how to stop it

Why you drool when sleeping and how to stop it

Drooling during sleep can often cause some concerns if it happens repeatedly, and most of us have drooled during our sleep at one point or another. Saliva (drool) production can often vary over a day from individual to individual and carries on while we are sleeping. These variations in production are probably due to our circadian rhythm. Saliva plays a vital role in keeping our mouth and throat lubricated, which is essential to good oral hygiene and health. 

Is drooling during sleep normal?

Drooling during your sleep is completely normal! The majority of us have probably drooled in our sleep at one point or another. Repeated drooling can cause things such as bad breath and dehydration, leading to feelings of embarrassment for the individual. Hopefully, this article can shed some light on why you may drool and the steps you can take to help stop or reduce the frequency of drooling while asleep. 

What causes drooling in sleep?

The most common cause of drooling during sleep is the over-production of saliva by your mouth. This is called sialorrhea or hypersalivation, and it becomes hard for an individual to keep all the saliva in their mouth. A typical situation is that you may notice you produce more saliva than usual when you smell delicious food. There are other things which may cause you to drool during your sleep. 

1. Sleeping positions

This can significantly impact how much drool you find on your pillows in the morning. If you sleep on your back, the excess saliva generally travels down your throat or stays in your mouth. Gravity is more likely to pull your saliva towards the pillow if you sleep on your side or stomach, resulting in drooling. If you also sleep with an open mouth while on your side or stomach, the chances of drool on your pillow increase. 

2. Illness

Things like colds, flu, strep throat and seasonal allergies can inflame your sinuses and block your airways (the sensation of a blocked nose). This will cause you to breathe through your mouth and drool more than usual. 

Gastroesophageal reflux disease (GORD)

Whilst heartburn is the most commonly recognised symptom of GORD, symptoms like drooling or dysphagia (difficulty swallowing) are also common. GORD often causes the sensation of a ‘throat lump’ and can cause individuals to drool more often. Furthermore, irritation to your oesophagus can trigger your body to produce more saliva, leading to more drooling. 

Obstructive sleep apnoea (OSA)

This is a sleep-related breathing disorder which causes temporary breathing pauses during an individual’s sleep. OSA is commonly associated with mouth breathing and can even worsen it. Due to the related open-mouth breathing, it can increase the chances of you drooling. OSA is a serious condition, and critical symptoms you must look out for are:

  1. Snoring
  2. Gasping
  3. Choking while asleep
  4. Waking up during the night
  5. Morning headaches
  6. Daytime sleepiness
  7. Lack of concentration during the day

If you suspect you have OSA, we would urge you to visit your local GP or a respiratory / ENT (ear nose and throat) sleep specialist as soon as possible for medical advice and appropriate treatment. 


Also known as teeth grinding, it is often accompanied by drooling and is associated with mouth breathing. If you are worried that you may be grinding your teeth, we recommend visiting your dentist to explore your options for reducing dental damage. Some studies have linked bruxism to anxiety and depression, which may require treatment. 

Medication side effects

If you take prescription medications and drool at night, it may be due to a side effect caused by one of your medications. Commonly, drugs which cause a drooling side effect are antipsychotics, antibiotics and medications used for Alzheimer’s.

Underlying medical conditions

Your nervous system stimulates your salivary glands, which may explain why excessive swallowing and drooling are common in neurodegenerative disorders. Conditions which may cause this are:

  1. Epiglottitis 
  2. Bell’s palsy
  3. Huntington’s
  4. Stroke
  5. Traumatic brain injury 
  6. Amyotrophic lateral sclerosis 

How can you stop drooling in your sleep?

In most cases, those who drool during their sleep do not require any treatments or medications because it is harmless. Thus, do not worry if you drool whilst asleep! Below, we have outlined some ways to reduce how much you dribble and tackle the causes of drooling we discussed above.

1. Changing sleeping positions

Those who sleep on their side or stomach have a higher chance of drooling whilst asleep. Consider trying to sleep on your back and trying measures such as breathing out of your nose and keeping your mouth closed as you sleep (such as by using mouth tape). You can learn more about different types of sleeping positions here. 

2. Treating allergies

If you drool at night and have allergies, it may be caused by your allergies. Consider visiting an allergy specialist or your local GP to commence treatment for your allergies if you haven’t already. It is vital to open up your sinuses to stop your mouth breathing, which may add to the increased drooling.

3. Treating OSA or bruxism

It is essential to visit a specialist and commence treatment for OSA if it is suspected or diagnosed. Treatment options may involve mandibular advancement devices designed to reduce snoring, drooling and grinding by keeping your lips closed and your teeth and tongue in the right place.  

4. Changing medication

If your medications are causing you to drool, consider speaking to your doctor or specialist to see if you can change them to reduce the drooling side effects. 

5. Other methods

In some cases, you may be able to have surgery or try Botox injections for hypersalivation. However, this is only sometimes necessary. We recommend speaking to a specialist and considering the methods listed above first to see if surgery/Botox injections are necessary as they carry their side effects and risks. 

Further information

As highlighted in this article, drooling during your sleep is normal and has happened to most of us at some point. In some cases, an underlying issue may be causing it. In such circumstances, you may notice other symptoms, and it is vital to contact your local GP for further guidance and advice on how to tackle the issue at hand. Once a cause has been identified, you can be started on an appropriate treatment plan. Many of my own patients have been worried about drooling in their sleep, or had questions about this topic. Hopefully the techniques listed above may be helpful to reduce the chances of you drooling during your sleep. 

I would recommend that everyone builds good sleeping habits to achieve a better night’s sleep, beginning with sleeping positions as highlighted above but also trying breathing techniques to help relax you, avoiding caffeine before bed, and increasing your deep sleep to achieve a more restful night. 



The articles in the Sleep Psychiatrist blog have been written by Dr Dipesh Mistry. They are for educational and informational purposes only, and should not be regarded as medical advice. Always seek advice from your sleep physician, personal physician, psychiatrist, or any other suitably qualified healthcare professional in relation to any interventions or treatment for your sleep, mental health or physical health.

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