Causes of Dry Mouth, Symptoms & Treatment Options

What is Dry Mouth?

Dry mouth, also called xerostomia, is a non-life-threatening oral condition. It occurs when the salivary glands in the mouth do not produce enough saliva to keep the mouth wet.

Dry mouth reduces a person’s quality of life because it affects simple day-to-day activities, such as tasting, eating, speaking, and swallowing. Untreated xerostomia can also lead to cavity formation and/or dental erosion.

Xerostomia naturally occurs during sleep and typically causes bad breath in the morning. Adults who sleep with their mouths open are more likely to experience dry mouth. Chronic dry mouth, on the other hand, is caused by diseases, medications, or problems with the salivary glands.

Connection Between Saliva and Tooth Decay

Specific components of saliva—such as calcium, phosphate, and bicarbonate—are key to maintaining good oral health. Saliva prevents tooth decay by protecting the enamel and controlling acid production caused by dental plaque bacteria.

When acid damages tooth enamel, saliva repairs the tooth's protective surface through remineralization. Saliva also protects against gum disease and cavities, among others.


Preserve your oral health with affordable preventive dental care.


When the production of saliva decreases over time, mouth dryness is more likely to occur, which can result in tooth decay or tooth loss.

dry mouth

Causes of Dry Mouth

Dry mouth is directly related to the autoimmune destruction of the salivary glands (Sjogren’s syndrome). It can also be indirectly related to cancer treatment, prescription medications, recreational drugs, aging, or other oral health conditions.

Common causes of dry mouth include:

Chemotherapy

Saliva can become thicker from chemotherapy treatment, which may dry out the mouth.

Radiation Therapy

Radiation therapy used to treat cancers of the neck, head, face, or salivary glands can increase mouth dryness.

Prescription Medications

Some prescription drugs can induce oral dryness, including antidepressants, anti-anxiety medications, muscle relaxants, pain medications, decongestants, and high blood pressure medications.

Aging

As people age, the risk of dry mouth increases. Oral dryness is also linked to long-term health conditions, poor nutrition, and certain medications. Snoring and mouth breathing may also cause dry mouth over time.

Diseases

Sjogren's syndrome attacks the glands that make tears and saliva. HIV/AIDS causes swollen salivary glands, which can also result in oral dryness. Other diseases associated with dry mouth include diabetes, hypertension, lymphoma, and hepatitis c.

Nerve Damage

Nerve damage to the neck or head caused by an injury or surgery can decrease saliva production.

Recreational Drugs

Excessive use of marijuana or amphetamines can cause dry mouth symptoms.

Tobacco

Tobacco slows down how fast you mouth produces saliva, thus leading to dry mouth.

Alcohol

Drinking alcohol excessively results in dehydration, which can also cause dry mouth.

bad breath

Symptoms of Dry Mouth

Symptoms can develop suddenly or gradually, depending on the patient’s lifestyle. Common signs of dry mouth include:

  • Dry mouth, throat, and tongue
  • Thickened saliva
  • Dry or cracked lips
  • Bad breath, specifically in the morning
  • Sore or scratchy throat
  • Abnormal voice changes or difficulty speaking
  • Abnormal changes in taste
  • Difficulty eating, chewing, and swallowing
dentist appointment

Dry Mouth Treatment Options & Prevention Tips

Xerostomia can be reversed with lifestyle changes. Depending on the condition’s severity, there are natural ways to reduce dry mouth, including:

  • Drinking water regularly to stay hydrated
  • Limiting dehydrating habits, such as drinking caffeine and alcohol too often
  • Taking over-the-counter saliva substitutes
  • Avoiding certain medications, such as decongestants and antihistamines
  • Stopping all tobacco use
  • Breathing through the nose
  • Avoiding sugary drinks and foods, such as candy and fruit juices
  • Chewing sugar-free gum (helps increase saliva production)
  • Brushing with fluoride toothpaste
  • Applying chapstick or lip moisturizer
cavity

Risk Factors of Untreated Dry Mouth

If dry mouth is left untreated, more serious oral conditions can develop, including:

Dental Caries & Tooth Decay

Cavities are caused by the interaction between microorganisms (Streptococcus Mutans), tooth structure (enamel), and a substrate (sugar). Dry mouth increases the risk of cavities because dental plaque is more difficult to remove. This condition also lowers the pH levels in the mouth, making it more acidic.

Common treatment options for cavities include fillings, inlays, onlays, and dental crowns. If cavities are left untreated, tooth decay progresses, which can lead to a root canal or tooth loss.

Dental Erosion

One of the most common risk factors of dry mouth is dental erosion, which occurs when acidic substances wear away tooth enamel. As saliva production decreases, teeth are less protected from decay-causing bacteria.

Gum Disease

A common risk factor of untreated dry mouth is gingivitis (minor gum infection) or periodontal disease (severe gum disease that attacks the gums and jawbone).

Periodontal disease is caused by poor oral hygiene, neglected dental treatment, dry mouth, and/or medications. Symptoms of gum disease include inflamed gums, bleeding gums, and high levels of dental plaque.

Mouth Sores

Mouth sores, ulcers, and canker sores are common risk factors of dry mouth.

Thrush (Yeast Infection)

Patients with dry mouth are more prone to developing oral thrush, also called a yeast infection.

Resources

“Dry Mouth.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Feb. 2018, www.mayoclinic.org/diseases-conditions/dry-mouth/diagnosis-treatment/drc-20356052.

Tucker, Abigail S., and Isabelle Miletich. Salivary Glands: Development, Adaptations, and Disease. Karger, 2010.

Updated on: June 29, 2020
Author
Alyssa Hill
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Medically Reviewed: September 30, 2019
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Lara Coseo
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