Why Do I Drool When I Sleep: 4 Main Causes

In your quest to finding answers to this question “why do I drool when I sleep?” you’ve all you think is right but to no avail. You’re still drooling. You’re now worried about the underlying health conditions that are associated with drooling. We understand your worries. We have your interest at heart and we have this as a package for you to give you relief, comfort, and to wipe away your shame. Are you ready to unwrap your package now?

Before we answer the question “why do I drool when I sleep?” it’s important to first understand what we’re talking about. Drooling can be defined as the process of letting saliva come out of one’s mouth. Drooling is also known as sialorrhea or hypersalivation. In most cases, people drool as a result of some underlying health complications in the throat, ears, or nose including certain neurological disorders.

For those bringing up infants, drooling is associated with teething and that is not anything to worry about. However, as an adult, when you’re waking up to drool patches on your pillow, it will be advisable that you find out the root cause. And now to answer your question “why do I drool when I sleep?” the following will explain why?

Allergies and Infections

Allergies and Infections

One common truth about humanity is that we’re created differently. And because of that, we respond to issues around us differently too. That means when your body is allergic to something the other person may not have the same experience. This is similar to infections. Meaning that, when your body is allergic to a condition or has an infection, it might respond by triggering the production of more saliva to remove the toxins. This process can easily make one drool when triggered by the following conditions:

  • Seasonal allergies
  • The sinus congestion is also known as Respiratory infections
  • Strep throat/pharyngitis and tonsillitis
  • Seasonal Allergies

Seasonal Allergies

This happens when the victim is experiencing general discomfort that comes with a running nose, itchy eyes, and sneezing. If this describes your situation, you may be suffering from seasonal allergies which is equally responsible for the production of excess saliva thereby causing you to drool. Careful attention should be taken when coming to contact with allergens pollens from various vegetations and mold.

  • Sinus Congestion

Sinus Congestion

The small hollow air spaces in the bones around the nose are known as sinuses. When these are subjected to nasal complications, allergies, and common cold they can easily become infected or flamed leading to a blockage that eventually results in unwanted flow coming in the form of drooling.

  • Strep Throat and Tonsillitis

Strep Throat

Strep throat is also known as pharyngitis or sore throat occurs when one is having difficulties in swallowing due to a paining throat. Normally this (pharyngitis) can either be viral or bacterial. You can easily notice this when you see red or white marks in the throat, experiencing fever, and having swollen glands. Other than this, the other area of concern is flamed or enlarged tonsils.

All this reduces the rate of swallowing which leads to retention of more saliva in the mouth opening the floodgate of saliva when sleeping as a drool. It is however worth noting that it may not be accurate to conclude that you have strep throat just from the underlying symptoms only. For better understanding your true condition, it is necessary that you consult with your physician periodically when these signs appear.

Because drooling can be embarrassing, it is important that when you suspect that allergies or infections are causing the discomfort of drooling, you may need to seek medical attention from your physician timely. This is important because, when treatment is administered early healing is guaranteed because drooling is a treatable health condition.’

Sleep Apnea

From the definition, drool is the unintentional flow of saliva from the mouth and because of this, drool will in most cases happen when you’re unconsciously asleep. When sleeping you don’t have any control of yourself especially when sleeping on your stomach or on your side. These sleeping position will facilitate an easy outflow of saliva from your mouth. Sleeping on your back would be ideal in curbing drooling.

drooling with sleep apnea

Having said that, how then does sleep apnea cause drooling? Sleep disorders like sleep apnea can cause you to drool because it blocks the airway. It doesn’t matter whether the sleep apnea is central or obstructive. All these conditions block the airway causing difficulties in breathing through the nose. And when breathing is distracted, more saliva is produced and retained in the mouth causing you to drool.

Life is a precious gift and must not be taken for granted. Therefore, you must not let sleep apnea bring you this discomfort and embarrassment. Seek help immediately from your primary healthcare giver for help. Upon assessment, they will advise if your condition only needs adjustment about your sleeping position or if it is serious and needs the touch of a specialist.

The Side Effect of Medications

Each time you get medication from your physician, they will tell you some of the side effects of the drugs they’re administering. The effects of medication can cause drooling as they are likely to increase the quantity of saliva in the body. This is mainly common with medications administered for Alzheimer’s disease, Myasthenia gravis, and Psychiatric disorders.

Side Effect of Medications

To address this, the patient must seek help from the specialist who administered the medication and not across the counter service.

Swallowing Difficulties Caused by Stroke/Neurological Disorders

Health conditions like stroke or some neurologic disorder can trigger dysphagia a condition that occurs when one is having difficulties in swallowing. Such conditions hinder even the swallowing of saliva. This then causes an excess of saliva which leads to drooling.

Swallowing Difficulties

Dysphagia is a condition associated with nervous system disorders like Bell’s Palsy, Parkinson's disease, and Amyotrophic lateral sclerosis. Stroke on the other hand hinders the smooth flow of blood to various parts of the body through to the brain which causes blood clots or a broken blood vessel. When treatment is not done timely, the patient can have a nervous system breakdown leading to difficulty in swallowing and drooling.

  • Epiglottitis


This is that rear infection-causing sudden swelling of the epiglottis which is a plate of cartilage just behind the throat essential for swallowing. And we’ve stated above, when swallowing is hindered, more saliva accumulates leading to drooling.

  • Guillain-Barre syndrome

Guillain-Barre syndrome

This is a very dangerous autoimmune disorder that kills nerves all over the body. Dead nerves don’t communicate to the brain hence less circulation leading to drooling.


You must have come to us curious about drooling in your sleep. I hope this article will answer your questions. This kind of situation is relatively common, so there is no need to panic when it happens. You just need to know the cause of this situation in time. In combination with the self-diagnosis above, see which type you fall into. If it is more serious, discuss it with your doctor.