Drooling

Why drooling happens

The salivary glands make roughly 1 to 1.5 liters of saliva a day. You swallow it automatically, hundreds of times a day, without noticing. Drooling happens when:

• saliva is not swallowed often or efficiently, because of nerve, muscle or coordination problems
• the lips do not seal, because of mouth breathing, facial weakness or the position of the head
• more saliva is made than usual, which is less common and is triggered by teething, mouth irritation, nausea and some medicines

Most drooling in adults and children with neurological conditions is a swallowing problem, not overproduction.

Drooling in babies and children

Drooling is normal in infants because lip and swallowing control develops gradually. It often increases at 3 to 6 months as saliva production rises and teething begins. Most children stop drooling during the day by 18 to 24 months, and nearly all by age 4.

Drooling in a child beyond this age is worth discussing with a doctor. Causes include:

• Enlarged tonsils and adenoids: large tonsils and adenoids force mouth breathing and crowd the throat, so saliva escapes. Clues are snoring, pauses in breathing at night, a nasal voice and daytime tiredness. A doctor diagnoses this by looking at the tonsils, sometimes with an X-ray of the adenoids or a sleep study. Removing them often reduces drooling.
• Cerebral palsy and other developmental conditions that affect mouth muscle control.
• Mouth ulcers, hand, foot and mouth disease, and other painful mouth infections that make swallowing hurt.

Drooling in adults

Common, minor causes

• Sleeping on your side or stomach with the mouth open
• A blocked nose from colds, allergies or sinusitis, forcing mouth breathing
• Dental problems, new dentures or braces
• Nausea and acid reflux, which both increase saliva
• Medicines such as clozapine and some other antipsychotics, pilocarpine, and medicines for Alzheimer's disease and myasthenia gravis

Neurological causes

• Parkinson's disease: reduced automatic swallowing, a stooped posture and a slightly open mouth cause drooling in many people with moderate to advanced disease.
• Stroke: weakness of the face and throat on one side.
• Bell's palsy: sudden weakness of one side of the face, with drooling from the corner of the mouth.
• ALS and myasthenia gravis: weakness of the swallowing and mouth muscles.
• Dementia, multiple sclerosis and brain injury.

Throat infections and emergencies

When swallowing becomes very painful, people let saliva drip out instead.

• Epiglottitis: swelling of the flap above the voice box. Sudden fever, severe sore throat, drooling, a muffled voice and leaning forward to breathe. It is a medical emergency.
• Peritonsillar abscess: a severe one-sided sore throat, a "hot potato" voice, difficulty opening the mouth and drooling.
• Allergic reactions with throat swelling.
• Swallowed objects, caustic chemicals and some poisons, including certain pesticides and mushrooms.

Drooling causes by age

How drooling is assessed

A doctor asks when the drooling started, how much there is, whether swallowing, speech or breathing has changed, and about medicines. They examine the mouth, teeth, tonsils, nose and face, and test facial and tongue movement. Depending on the findings:

• a speech and language therapist assesses swallowing, sometimes with a video X-ray swallow study or a camera through the nose
• children with large tonsils may need a sleep study
• neurological causes may need brain imaging

Drooling that leads to coughing or choking on saliva raises the risk of aspiration pneumonia and should be reviewed.

Treatment for drooling

Simple measures

• Treat nasal blockage so you can breathe through your nose
• Sleep on your back, or raise the head of the bed
• Review medicines that may increase saliva
• Have dental problems and ill-fitting dentures fixed
• Keep the skin around the mouth dry and protected with a barrier cream to prevent soreness

Therapy

Speech and language therapists teach exercises to improve lip closure, tongue control and swallowing frequency, along with posture changes. Reminder techniques, such as a regular cue to swallow, help some people with Parkinson's disease.

Medicines and procedures

• Anticholinergic medicines such as glycopyrrolate, or scopolamine patches, reduce saliva. Side effects include dry mouth, constipation, blurred vision and confusion, so they need careful monitoring, especially in older adults.
• Botulinum toxin injections into the salivary glands reduce saliva for 3 to 6 months.
• Surgery to remove or reposition salivary glands or tie off ducts is reserved for severe cases that do not respond to other treatment.
• Tonsil and adenoid removal for children whose drooling is linked to large tonsils.

Frequently asked questions

Why do I drool when I sleep?

Night drooling is very common. Sleeping on your side or stomach, a blocked nose, allergies and reflux all encourage the mouth to fall open and let saliva out. It is usually harmless. Drooling with loud snoring and gasping may point to sleep apnea and is worth checking.

Can enlarged tonsils cause drooling?

Yes. Large tonsils and adenoids force mouth breathing and crowd the throat, so saliva escapes. Doctors diagnose this by examining the throat, sometimes with an X-ray of the adenoids or a sleep study. Removing the tonsils and adenoids often helps if drooling or sleep-disordered breathing is significant.

When is drooling an emergency?

Sudden drooling with severe sore throat, fever, a muffled voice, noisy breathing or difficulty breathing can mean epiglottitis or a throat abscess. Drooling with face or tongue swelling may be anaphylaxis. Drooling with facial droop may be a stroke. Call 911 or your local emergency number.

Is drooling a sign of a stroke?

It can be. Sudden drooling from one side of the mouth together with facial droop, arm weakness or slurred speech is a warning sign of stroke. Bell's palsy causes similar one-sided facial weakness but without arm weakness or speech problems. Both need prompt medical assessment.

When do babies stop drooling?

Most children stop drooling during the day by 18 to 24 months as lip and swallowing control matures. Some drool at night or when concentrating until age 4. Drooling after that age should be discussed with your pediatrician.