What Is Dry Mouth During Sleep?

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You shouldn’t need to drink water at night. Normally, your body’s natural fluid balance lets you get eight hours or longer of uninterrupted sleep without having to drink or eat. So, if you wake up with a dry throat at night, there is probably an underlying reason, like mouth breathing, a sleep disorder, or another health condition.

What causes dry mouth and throat dryness during sleep? This article explains why your need for a nighttime glass of water might signify other problems. It also goes over symptoms, diagnosis, and treatment of dry throat.

White roses, alarm clock and water glass on bedside table
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Dry Mouth During Sleep Symptoms

Most people drink water at night simply because their mouth becomes dry. Dry mouth during sleep is sometimes called xerostomia.

Feeling thirsty at night can range from relatively minor to extreme. Sometimes your tongue or throat can feel as dry as a bone.

In addition to a dry tongue and throat, you may notice other symptoms, like:


Several conditions may contribute to a dry mouth. They range from medication side effects to sleep or health conditions.


One of the more common causes of thirst at night is using medications that cause dryness.

These can include:

If you are taking medications, review your medication list with your pharmacist or healthcare provider. They can help you identify any potential culprits. For example, if the symptom started with the use or increased dose of a medication, it could be the cause.

Health Conditions

There are also medical conditions that might cause mouth dryness. Typically, these disorders also cause other symptoms.

Conditions that can cause dry mouth include:

Mouth Breathing

Many people experience dry mouth at night simply because they are breathing through their mouth when they sleep. Mouth breathing more likely occurs when the nasal passages are blocked.

This kind of congestion can happen with:

By default, you breathe through your nose. Nasal breathing reduces the loss of moisture from the soft tissues that line your airways. However, when you breathe through your mouth, the movement of the air quickly dries you out.

Sleep Disorders

Mouth breathing at night is often associated with snoring. It may also be a symptom of sleep apnea. These conditions may be worse when you sleep on your back or use alcohol near bedtime.

Needing to drink water at night may be an early sign that you cannot breathe well while you sleep.

Mouth breathing during sleep may put you at higher risk of other sleep disorders that affect your breathing at night. For example, if you use continuous positive airway pressure (CPAP) to treat sleep apnea, air escaping with mouth breathing may worsen the dryness.


If you frequently experience dry mouth at night, speak with your healthcare provider about your concerns. They can begin to consider whether medications or health problems are causing it.

Your doctor will perform a physical exam and take a medical history to determine whether you may have a health condition contributing to your dry mouth.

In addition, they might perform specific tests, including:

Depending on these initial tests, your doctor may investigate your breathing during sleep with a sleep study.


To treat your mouth dryness, you may need to start by ensuring proper airflow through your nose. Treatment for improving airflow includes:

Lifestyle and self-care steps can also help. These include:

  • Avoiding sugar
  • Chewing sugarless gum
  • Drinking enough water
  • Consuming less caffeine
  • Avoiding tobacco and alcohol
  • Using a humidifier in your bedroom


Dry throat and dry mouth at night can have unpleasant effects, including cracked lips, bad breath, mouth and tooth infections, and difficulty talking or swallowing. A range of factors may cause dry mouth, including some health conditions and sleep apnea. Certain medications may also have a side effect of dry mouth. Treatment depends on the cause.

A Word From Verywell

You don’t have to keep a glass of water on your nightstand. If you have mouth dryness at night, seek evaluation and get back to breathing—and sleeping—better.

Frequently Asked Questions

  • Why do I wake up with a stuffy nose and dry mouth?

    Nasal congestion can be one reason for waking up with a dry mouth and stuffy nose. Nasal congestion is caused by swelling in the nasal passage tissues, which narrows airways and makes it hard to breathe through the nose. Nighttime nasal congestion can be caused by allergies to something in your bedroom—like dust mites, pet dander, or mold—an upper respiratory infection, or even acid reflux.

  • Is sleep apnea related to dry mouth?

    Dry mouth upon waking is one symptom of sleep apnea, a breathing disorder that causes repeated pauses in breathing during sleep. Other symptoms can include chronic snoring, choking or gasping while asleep, teeth grinding or clenching, and night sweats, among others.

    If you experience these symptoms, tell your healthcare provider.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Dental Association. Xerostomia (dry mouth).

  2. Wolff A, Joshi RK, Ekström J, et al. A guide to medications inducing salivary gland dysfunction, xerostomia, and subjective sialorrhea: a systematic review sponsored by the World Workshop on Oral Medicine VI. Drugs R D. 2017;17(1):1-28. doi:10.1007/s40268-016-0153-9

  3. National Institute of Dental and Craniofacial Research. Dry mouth.

  4. Stupak HD. Strategies for addressing mouth-breathing treatment with an “adequate” nose. In: Rethinking Rhinoplasty and Facial Surgery. Cham, Switzerland: Springer International Publishing; 2020:193-207. doi:10.1007/978-3-030-44674-1_9

  5. Zhang C, Shen Y, Liping F, Ma J, Wang GF. The role of dry mouth in screening sleep apnea. Postgrad Med J. 2021;97(1147):294-298. doi:10.1136/postgradmedj-2020-137619

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.