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.
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.
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 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:
Saliva can become thicker from chemotherapy treatment, which may dry out the mouth.
Radiation therapy used to treat cancers of the neck, head, face, or salivary glands can increase mouth dryness.
Some prescription drugs can induce oral dryness, including antidepressants, anti-anxiety medications, muscle relaxants, pain medications, decongestants, and high blood pressure medications.
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.
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 to the neck or head caused by an injury or surgery can decrease saliva production.
Excessive use of marijuana or amphetamines can cause dry mouth symptoms.
Tobacco slows down how fast you mouth produces saliva, thus leading to dry mouth.
Drinking alcohol excessively results in dehydration, which can also cause dry mouth.
Symptoms can develop suddenly or gradually, depending on the patient’s lifestyle. Common signs of dry mouth include:
Xerostomia can be reversed with lifestyle changes. Depending on the condition’s severity, there are natural ways to reduce dry mouth, including:
If dry mouth is left untreated, more serious oral conditions can develop, including:
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.
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.
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, ulcers, and canker sores are common risk factors of dry mouth.
Patients with dry mouth are more prone to developing oral thrush, also called a yeast infection.
While dry mouth is often caused by dehydration, it is not the only risk factor. Dry mouth is also a side effect of taking certain medications, such as antidepressants, antihistamines, muscle relaxants, appetite suppressors, diuretics, and decongestants.
Medical conditions, such as yeast infections, autoimmune diseases, HIV/AIDS, certain cancers, diabetes, mouth breathing, snoring, and sleep apnea can also cause dry mouth.
People with diabetes are more prone to developing dry mouth and thrush (yeast infections). A side effect of diabetes is decreased salivary production, which can lead to increased thirst and dry mouth.
Anxiety can cause dry mouth. Anxiety-related dry mouth is often accompanied by other symptoms, including sweating, increased heart rate, trouble focusing, restlessness, and shaking.
Dry mouth medications, such as Evoxac (cevimeline) and Salagen (pilocarpine), can help increase saliva flow. You can also take over-the-counter artificial saliva supplements.
“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.