Dry mouth, or xerostomia, occurs when a person’s salivary glands do not produce enough saliva to keep the mouth moist. Xerostomia can be a symptom of diabetes and also a side effect of the medication that treats diabetes.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), dry mouth is a common symptom of diabetes.

In this article, we look at the symptoms of dry mouth and its link with diabetes. We also explain how a person can treat dry mouth.

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Dry mouth occurs when there is not enough saliva in the mouth.

According to the NIDDK, people with dry mouth may experience:

  • a frequent dry feeling in the mouth
  • mouth pain
  • a rough, dry tongue
  • difficulty eating, talking, chewing, or swallowing
  • sores or infections in the mouth

In addition, the American Dental Association (ADA) note that dry mouth may involve:

  • a sore throat
  • nasal dryness
  • hoarseness

The NIDDK list dry mouth among the most common problems that people living with diabetes experience.

Its high prevalence in this population may be due to:

  • Dehydration: People with diabetes are prone to dehydration.
  • Increased blood sugar levels: In those with diabetes, a person’s blood glucose levels can become too high. The term for this is hyperglycemia, and it can cause a person to experience dry mouth.
  • Kidney conditions: Over time, high blood glucose can lead to kidney disease, which can cause dry mouth.
  • Diabetes medication: Some medications that a person can take to help control diabetes can cause dry mouth as a side effect.

Also, according to Johns Hopkins Medicine, approximately two-thirds of those with diabetes have high blood pressure or use medications to help control hypertension. Dry mouth can occur as a side effect of these medications.

Is dry mouth a symptom of diabetes?

According to a 2014 review, dry mouth can be a warning sign of diabetes. However, although it is common in those with diabetes, it is not the only symptom.

A person may potentially experience several symptoms due to diabetes, including:

  • blurry vision
  • fatigue
  • increased thirst
  • more frequent urination
  • increased hunger
  • unexplained weight loss
  • tingling or numbness in the extremities, such as the hands or feet
  • sores that do not heal

Although both type 1 and type 2 diabetes have similar symptoms, the NIDDK state that they do not develop in the same way.

They note that while people who develop type 1 diabetes usually experience a fast onset of symptoms, people living with type 2 diabetes tend to see a gradual onset of symptoms, which they may not notice until another complication develops, such as blurred vision.

People who experience dry mouth as a result of medication can ask a doctor about the possibility of switching medications. Managing any underlying conditions — for example, keeping blood sugar levels within a safe range to control diabetes — may also help.

Healthcare professionals can also prescribe medications to stimulate saliva production. These include pilocarpine (Isopto Carpine), which has a typical dosage of 5 milligrams (mg) three times a day, and cevimeline (Evoxac), which has a typical dosage of 30 mg three times a day.

A person will need to take these medications for 3 months to ensure that they are working.

A person can also try saliva substitutes that come in the form of gels, sprays, and lozenges. However, the authors of a 2020 article note that these do not work reliably and that when they do, they only provide temporary relief.

Home remedies

The National Institute of Dental and Craniofacial Research recommend that a person take the following steps to minimize the symptoms of dry mouth:

  • avoiding spicy or salty foods because they can aggravate the mouth
  • sipping water slowly throughout the day
  • chewing sugar-free gum or sucking on sugar-free candy to help stimulate saliva production
  • sipping water or other sugar-free drinks during meals to aid swallowing
  • refraining from alcohol or tobacco use
  • using a humidifier when sleeping
  • avoiding caffeinated beverages

Diabetes and the medications that doctors use to treat it are not the only reasons why a person may experience dry mouth.

Researchers state that xerostomia most commonly occurs as a side effect of over-the-counter and prescription medications, including:

It can also occur due to autoimmune conditions, such as:

Other possible causes include:

  • breathing through the mouth
  • dehydration
  • nerve damage due to a neck or head injury
  • end stage renal disease
  • HIV

The ADA note that saliva plays several important roles in the mouth, which include:

  • maintaining the health of the soft and hard tissues
  • washing away food and debris
  • neutralizing the acids in the mouth that bacteria produce
  • helping fight against microbes and overgrowth that may lead to disease

If a person does not receive treatment, dry mouth can lead to tooth decay, gingivitis, periodontitis, and oral thrush.

The NIDDK recommend that people take several steps to help keep their mouth healthy, including:

  • making regular visits to the dentist
  • using fluoride toothpaste
  • drinking water that contains fluoride
  • eating a healthful diet
  • using dental floss
  • using a mouthwash designed to help prevent cavities and gum disease

A person should contact a doctor if they develop symptoms of dry mouth that do not resolve. Diabetes is one of several potential causes that a doctor can help rule out.

In some cases, medications may be the cause. In these cases, a person can talk with a doctor about switching medications. It is essential not to stop taking a prescription medication without consulting a doctor first.

People with diabetes have a higher chance of experiencing dry mouth than those without this condition. In some cases, dry mouth may be the result of diabetes medication.

However, other health conditions and medications can cause dry mouth, so it is not necessarily a sign of diabetes.

A person should talk with a doctor if they develop persistent dry mouth. The doctor can determine the cause and suggest the best course of action.