Waking up with a dry mouth at night is common, but if it happens regularly, it can have several different causes. Here are eight possibilities:
- Mouth breathing — Sleeping with your mouth open, often because of nasal congestion, can dry the mouth.
- Nasal blockage — Allergies, a cold, sinus problems, or a deviated nasal septum can make you breathe through your mouth.
- Dehydration — Not getting enough fluids during the day can contribute to dry mouth, although excessive nighttime thirst has other possible causes.
- Medications — Many medicines can reduce saliva production, including some antihistamines, antidepressants, blood-pressure medicines, and decongestants.
- Snoring or sleep apnea — People who snore or have obstructive sleep apnea may breathe through their mouth during sleep.
- Alcohol or tobacco use — Alcohol can contribute to dehydration, while smoking can irritate the mouth and affect saliva production.
- High blood sugar/diabetes — Persistent thirst and dry mouth can occur with elevated blood glucose, particularly when accompanied by frequent urination.
- Medical conditions affecting saliva — Certain autoimmune or other conditions can reduce saliva production and cause persistent dry mouth
