Waking up with a dry mouth may indicate an underlying health condition if it happens regularly. People who often experience dry mouth may find it disrupts their sleep and affects their dental health.

Dry mouth — also known as xerostomia — occurs when a person does not have enough saliva to keep the insides of their mouth moist.

People with dry mouths are more likely to experience oral fungal infections and tooth decay, as saliva helps protect against them. A dry mouth can also lead to bad breath or a sore throat.

There are many reasons people may wake up with a dry mouth. If the person is feeling stressed or anxious, they may experience a dry mouth, but sometimes it can be a sign of an underlying illness.

This article considers the different causes of dry mouth and explains how people can help avoid it.

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The most common cause of dry mouth is a side effect of medication. Many medications may lead to a dry mouth when waking up. These include:

People should inform a doctor if any side effects persist. Doctors may recommend a different medication or alter the dose to help with dry mouth.

In sleep apnea-hypopnea syndrome (SAHS), a person’s airways become partially blocked while sleeping. This condition can make people snore and breathe through their mouths.

According to a 2020 study, individuals with SAHS are more likely to experience a dry mouth on waking than those without.

Doctors may prescribe continuous positive airway pressure (CPAP) therapy to people with SAHS. However, the above study found that individuals receiving this treatment were more likely to experience dry mouth on waking. Researchers noted that the symptoms usually disappeared during the day.

People receiving radiation therapy in the head and neck area may experience dry mouth on waking, as the treatment can damage the salivary glands and mouth cavity. They may find that their salvia is thicker than usual and more sticky.

The American Cancer Society (ACS) also notes that some types of chemotherapy and cancer medications can make people’s mouths dry. These treatments can also irritate or damage the salivary glands.

Some people with autoimmune diseases may experience dry mouth. It is particularly notable with Sjögren disease, where a person’s immune system attacks healthy, moisture-producing cells. People with Sjögren disease may also experience dry eyes.

Other autoimmune diseases that could cause a dry mouth include:

People with diabetes may also experience dry mouth in the mornings if their blood sugar levels are high. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) adds that some medications for diabetes can interfere with a person’s salivary glands, which can cause dry mouth.

A 2020 article also suggests that certain medications may make people with Alzheimer’s disease more likely to experience dry mouth.

According to the Alzheimer’s Society in the United Kingdom, people with dementia or Alzheimer’s disease may lose the ability to recognize when they are thirsty and may not drink enough liquid to keep them hydrated. This could lead to dry mouth when they wake up.

According to the National Health Service (NHS) in the U.K., dehydration is a common cause of dry mouth when waking up. This could occur from:

Substances such as cigarette smoke, alcohol, and caffeine may also give a person a dry mouth in the morning.

Some steps that people can take to prevent waking up with a dry mouth include:

  • cutting down on or eliminating coffee and caffeinated sodas
  • avoiding tobacco and alcohol
  • chewing sugar-free gum
  • sucking sugar-free candy
  • increasing fluid intake by drinking more water
  • being diligent about oral hygiene
  • sucking on ice chips

If this symptom persists, people with dry mouths can consult a doctor to understand the cause and manage any potential underlying diseases. For example, people with diabetes may get advice about how to manage their blood sugar levels.

Doctors may recommend different medications or combinations of medications to treat underlying conditions that can cause dry mouth.

Talking with a doctor may also help if a person is experiencing frequent thrush infections in their mouth or has recurrent ulcers or mouth sores.

During a diagnosis, a doctor may check that the person’s salivary glands are producing enough saliva. They may recommend artificial saliva sprays, lozenges, or gels, but these may only work for a limited time, and some people may not like the taste.

Waking up with a dry mouth occurs to everyone occasionally, but when it is a regular occurrence, people may experience sore throats, fungal infections, tooth decay, and bad breath.

Some medications, or combinations of medications, can cause dry mouth in the mornings. Doctors may be able to change the dosage or recommend different medications if a person experiences this.

Some underlying conditions — including diabetes, Sjögren disease, and Alzheimer’s disease — can lead to dry mouth.

Keeping hydrated, chewing sugar-free gum, and reducing caffeine and alcohol can help. If a person smokes, stopping smoking may also reduce the symptoms of dry mouth.