Waking up with a damp pillow?

You’re not alone.

Drooling during sleep is more common than you think — and in most cases, it’s completely normal.

Your body produces about 2–4 cups of saliva daily, and while you're awake, you swallow it unconsciously. But when you’re asleep — especially if you're relaxed or lying in certain positions — some of that saliva can escape.

But could frequent drooling ever signal something deeper?

Let’s explore the real causes of nighttime drooling, when it’s just a quirk of anatomy or habit, and when it might be worth discussing with your doctor.

Spoiler: Most reasons are harmless. But awareness matters.

✅ Common & Harmless Causes of Nighttime Drooling


Sleeping on Your Side or Stomach	Gravity pulls saliva toward the corner of your mouth
Mouth Breathing	Often due to nasal congestion from allergies, colds, or deviated septum — keeps mouth open and increases drool
Obstructive Sleep Apnea (OSA)	People with OSA often breathe through their mouths and have poor muscle control during sleep
Acid Reflux (GERD)	Extra saliva production neutralizes stomach acid — some leaks out while sleeping
Medications	Some drugs (like sedatives, antipsychotics, or seizure medications) increase saliva production or reduce swallowing reflexes
Teeth Grinding (Bruxism)	Jaw clenching can stimulate salivary glands and lead to drooling