Waking up to a damp pillow is more common than you might think. For many people, drooling during sleep is simply a harmless quirk caused by sleeping on your side, being deeply relaxed, or having an especially tiring day. However, if it happens often, in large amounts, or begins suddenly, it can sometimes be more than just an inconvenience.
Persistent nighttime drooling, medically known as sialorrhea, may be a sign of an underlying health condition. While occasional drooling is normal, ongoing or excessive drooling, especially when accompanied by other symptoms, should not be ignored. One possible cause is sleep apnea, a condition where breathing repeatedly stops and starts during the night, often due to a blocked airway.
This can force you to breathe through your mouth, disrupt the normal swallowing reflex, and cause saliva to pool and escape. Gastroesophageal reflux disease (GERD) can also lead to drooling, as acid reflux stimulates excess saliva production, which may overflow while lying down. Neurological disorders such as Parkinson’s disease, ALS, stroke, or cerebral palsy can impair the muscles and nerves involved in swallowing, leading to saliva buildup.
Allergies, sinus infections, or nasal blockages can force mouth breathing, which sometimes triggers drooling during sleep. Certain medications, including some antipsychotics, Alzheimer’s treatments, seizure drugs, and anti-nausea medicines, can overstimulate salivary glands, while dental problems like misaligned teeth, gum disease, or ill-fitting dentures can interfere with proper swallowing and mouth closure.
Occasional drooling is generally harmless, but you should see a doctor if it happens frequently, soaks your pillow, is accompanied by difficulty swallowing, choking during meals, muscle weakness, slurred speech, daytime fatigue, or breathing problems, or if it begins suddenly or worsens. Drooling may seem like a minor issue, but it can sometimes be your body’s subtle way of signaling a more serious problem. Paying attention to these signs can help you identify and address the root cause before it becomes something more serious.