7 reasons why you drool in your sleep and how to prevent it

• Most people produce excess saliva while they sleep and drooling is usually not serious.
• You are more likely to drool if you have conditions like sleep apnea or acid reflux.

You wake up from a deep sleep to find your pillow wet or your cheek slick with saliva. Drooling in your sleep can be inconvenient and embarrassing, especially if you're sleeping next to someone you're trying to impress or dozing in a semi-public place like an airport terminal.

Though it may be bothersome, "drooling is natural and is not usually concerning," says Dr. Neal H. Patel, a family medicine physician with Providence St. Joseph Hospital.

However, some minor medical issues like dry mouth can make you drool more — and, though rare, some serious conditions like neurological disease can also have the same effect.

Here are some of the causes of drooling in your sleep and how to help reduce it.

1. Dry mouth

When your mouth is dry, salivary glands activate to lubricate it, Patel says. So, if you're dehydrated or sleep with your mouth open, those glands could produce more saliva, leading you to drool in your sleep.

How to treat it: Stay well hydrated during the day. Then, keep a glass of water next to the bed to sip if you wake up thirsty throughout the night.

2. Allergies and infection

When you're sick with an upper respiratory infection or seasonal allergies, your body produces more saliva. This can help flush germs or irritants from your nose, throat and mouth —but it can also make it more likely that you drool during your sleep, says Dr. Thomas Michael Kilkenny, director of Institute Sleep Medicine at Staten Island University Hospital.

Allergies can also cause a blocked nose, which forces you to breathe through your mouth. This can dry it out and trigger saliva production in your sleep.

How to treat it: Treat seasonal allergies with over-the-counter antihistamines like Claritin or Zyrtec, Patel says. If you have an upper respiratory infection you might need to let the illness run its course. But if it lasts more than a week or two, reach out to your doctor for advice.

3. Acid reflux

Some people with acid reflux experience excess saliva as a symptom of the condition, Patel says. This can lead to drooling during sleep, since eating a large dinner and laying down in bed can both make acid reflux worse.

How to treat it: Focus on treating acid reflux with home remedies like increasing fiber intake and lifestyle changes, like eating smaller meals. When your reflux is acting up, over-the-counter antacids can help, but if you have to take them regularly you should talk with your doctor.

4. Sleep apnea

Sleep apnea is a condition that impairs people's ability to breathe while they sleep. The irregular breathing patterns this causes can make people breathe through their mouths and increase their risk of drooling during sleep, Patel says.

In addition, people with sleep apnea are more likely to have other conditions including sleep bruxism, or teeth grinding, which can also increase the likelihood of drooling since grinding stimulates the salivary glands.

How to treat it: If you think you have sleep apnea, or experience other symptoms like fatigue or snoring, talk with your doctor. Treatments include lifestyle changes like losing weight, if you're overweight, and devices to regulate your breathing like a CPAP machine.

5. Medication side effects

Some medications increase your saliva production. This is known as drug-induced sialorrhea, or hypersalivation, and it can make you more likely to drool at night. These medications are:

• Antipsychotic medications including risperidone or clozapine
• Cholinergic agonists that are used treat dementia

How to treat it: If you notice an uptick in drooling after starting a new medication, talk to your doctor. Have an open conversation about the benefits of the medication versus the inconvenience of drooling at night.

6. Neurological disease

Any condition that affects the neurological system can affect your saliva production, make it difficult to keep your mouth closed at night, or affect your ability to swallow, Kilkenny says.

Because of that, Parkinson's disease, cerebral palsy, and stroke can all increase the risk of drooling at night. If you have one of these conditions, you'll also notice other symptoms of neurological disease like headaches, changes to your memory or cognitive ability, or tremors.

How to treat it: Talk to your doctor about medications that can reduce your saliva production. Working with a neurologist and speech, physical, and occupational therapists may also help, although the impact of behavioral interventions are limited when you're unconscious during sleep, Kilkenny points out.

7. Sleep position

Sleeping on your stomach or side can make it more likely that saliva slips from your mouth while you sleep thanks to the pull of gravity.

How to treat it: Consider training yourself to sleep on your back, or pay special attention to sleeping with your mouth closed.

Insider's takeaway

Most people will wake up with a wet pillow or cheek at one time or another.

"Minor drooling is a very common condition," Kilkenny says.

But if you notice any sudden changes or your drooling impacts your quality of sleep, don't hesitate to speak with your doctor. In addition to the lifestyle changes outlined above, there are more aggressive treatments or drooling, including prescription medications to reduce saliva production and help diminish nighttime drooling, Patel says.

"You know your body better than anybody else so if you are concerned or worried, please contact your health care provider immediately," he says.