Dry mouth at night (also called nocturnal xerostomia) can be both uncomfortable and disruptive to sleep. It’s often a symptom of an underlying issue rather than a disease itself.
Here are 8 common reasons why you might be experiencing it:
1. Mouth Breathing
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Why it happens: Breathing through your mouth while asleep—due to nasal congestion, allergies, a deviated septum, or sleep apnea—causes saliva to evaporate faster than it can be replenished.
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Signs: Waking with a very dry mouth, sore throat, or bad breath; often snoring.
2. Medications
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Why it happens: Hundreds of medications list dry mouth as a common side effect. These include drugs for:
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Depression and anxiety
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Allergies (antihistamines)
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High blood pressure
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Pain
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Asthma (bronchodilators)
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Overactive bladder
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Signs: Dryness that started or worsened after beginning a new medication.
3. Dehydration
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Why it happens: Not drinking enough fluids during the day, consuming diuretics (like caffeine or alcohol) in the evening, or sweating heavily at night can reduce your body’s fluid levels, limiting saliva production.
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Signs: Dark yellow urine, thirst, and dry mouth throughout the day as well.
4. Underlying Health Conditions
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Why it happens: Certain diseases affect the salivary glands or the body’s ability to produce moisture.
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Sjögren’s Syndrome: An autoimmune disorder that attacks moisture-producing glands.
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Diabetes: Especially if blood sugar is poorly controlled, leading to dehydration.
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HIV/AIDS
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Parkinson’s & Alzheimer’s
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Stroke
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5. Aging
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Why it happens: While not directly caused by age itself, older adults are more likely to take medications that cause dry mouth and have other health conditions that contribute. Changes in the body’s ability to process medications and nutritional deficits can also play a role.
6. Lifestyle Factors
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Why it happens:
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Smoking or vaping: Chemicals in tobacco and e-cigarettes can reduce saliva flow and irritate the mouth.
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Alcohol consumption: Alcohol is dehydrating, and drinking it in the evening can lead to nighttime dryness.
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High-salt diet: Can contribute to fluid imbalance if not offset with enough water.
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7. Nerve Damage
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Why it happens: Injury or surgery to the head or neck area (e.g., dental surgery, cancer radiation treatment) can damage the nerves that signal salivary glands to produce saliva.
8. Sleep Disorders
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Why it happens:
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Sleep Apnea: This condition often leads to mouth breathing. Additionally, CPAP machines, if not properly humidified, can blow dry air into the mouth, worsening dryness.
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Snoring: Chronic, heavy snoring goes hand-in-hand with mouth breathing.
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When to See a Doctor or Dentist
Consult a healthcare professional if:
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The dryness is persistent and doesn’t improve with simple remedies.
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You have difficulty chewing, swallowing, or speaking.
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You have a persistently sore throat, hoarseness, or mouth sores.
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You suspect it’s linked to a medication or a new health symptom.
A doctor or dentist can help identify the root cause—through a review of your medications, health history, and possibly blood tests or salivary flow measurements—and recommend appropriate treatment, which may include medication adjustments, saliva substitutes, or addressing an underlying condition.