Waking up in the middle of the night with a dry, sticky mouth can be uncomfortable—and sometimes worrying. While occasional dryness is usually harmless, frequent nighttime dry mouth (also called xerostomia) may be your body’s way of signaling an underlying issue. Here are eight common reasons your mouth feels dry at night—and what they might mean.
1. Sleeping With Your Mouth Open
One of the most common causes of nighttime dry mouth is mouth breathing. If your nose is congested due to allergies, a cold, or a deviated septum, you may breathe through your mouth while sleeping, allowing saliva to evaporate quickly.
2. Dehydration
Not drinking enough water during the day—or losing fluids through sweating, exercise, or caffeine—can reduce saliva production at night. Alcohol before bed can also worsen dehydration.
3. Medications
Many common medications list dry mouth as a side effect, including:
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Antihistamines
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Antidepressants
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Blood pressure medications
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Pain relievers
If dryness started after a new prescription, this could be the cause.