Quick answer: Waking with a dry mouth can be caused by mouth breathing, medication, dehydration, a blocked nose, or an underlying condition. Sip water and review possible causes, but see a dentist or clinician if it persists. Saliva protects teeth, so ongoing dryness deserves attention.
Why does my mouth get dry at night?
Saliva naturally decreases during sleep. When the mouth becomes unusually dry, several factors may contribute:
- Mouth breathing or nasal congestion: Allergies, a cold or another obstruction can make breathing through the nose difficult.
- Medications: Many prescription and over-the-counter drugs can reduce saliva. Ask your clinician or pharmacist about your medicines; do not stop prescribed treatment on your own.
- Dehydration: Not drinking enough, fever, vomiting or diarrhea can leave your mouth dry.
- CPAP or other sleep equipment: Air leaks or insufficient humidification can contribute to dryness.
- Health conditions: Diabetes, Sjögren’s disease and other conditions can be associated with dry mouth. A symptom alone cannot establish the cause.
The National Institute of Dental and Craniofacial Research explains that persistent dry mouth can affect eating, speaking and dental health.
What can you do tonight?
- Keep water nearby. Take small sips when needed and drink regularly during the day, unless your clinician has advised fluid restriction.
- Address a blocked nose. A saline nasal spray may help some people. Ask a pharmacist or clinician about persistent congestion and appropriate treatments.
- Consider a clean humidifier. Dry room air may make your mouth and nose feel uncomfortable. Follow the manufacturer’s cleaning instructions and avoid excessive room humidity. Yawnder has previously discussed humidifiers with visitors in its San Diego showroom; their usefulness depends on the cause of the dryness.
- Protect your teeth. Brush with fluoride toothpaste, keep dental appointments and ask your dentist about saliva substitutes or other products. Sugar-free gum or lozenges can stimulate saliva while you are awake; do not sleep with them in your mouth.
- Notice triggers. Alcohol, tobacco and caffeine can contribute to dryness for some people. Track symptoms and habits to discuss with your clinician.
Avoid taping your mouth shut to force nasal breathing, especially if your nose is blocked or you may have sleep apnea. It does not address the underlying cause and can make breathing harder.
Dry mouth while using CPAP
Check the mask fit and tubing for leaks and review your device’s humidification settings with your sleep clinician or equipment supplier. If you breathe through your mouth, you may need a different mask or another adjustment. Do not stop prescribed CPAP without discussing the problem with your care team. The National Heart, Lung, and Blood Institute describes ways to address common CPAP problems.
When to see a dentist or clinician
Make an appointment if dryness persists, causes trouble swallowing or speaking, or comes with mouth sores, dental problems or changes in taste. Tell your clinician if you also snore loudly, wake gasping, or feel unusually sleepy in the daytime; these can be signs of sleep apnea. Excessive thirst and frequent urination also merit medical evaluation.
Seek urgent help for difficulty breathing or an inability to swallow. Bring a list of medications and note when the dryness started, whether your nose is blocked and whether you use CPAP.
Frequently asked questions
Does dry mouth mean I have sleep apnea?
No. Mouth breathing can occur with sleep apnea, but dryness has many possible causes. A clinician can assess symptoms and decide whether testing is appropriate.
Will drinking water cure it?
Water can relieve dryness temporarily, especially when dehydration contributes. It may not resolve reduced saliva, a medication effect or a breathing problem.
Can dry mouth harm teeth?
Yes. Saliva helps protect teeth, and persistent dryness can increase the risk of cavities. Ask your dentist about a prevention plan.