Dry mouth, also known as xerostomia, occurs when the salivary glands in the mouth do not produce enough saliva to keep it moist. Most people experience dry mouth once in a while, such as when they are nervous, upset or under stress. Dry mouth can also be a symptom of inadequate fluid intake, which can result in dehydration (loss of fluids from the body).

Occasional xerostomia is not usually a cause for concern and can be relieved by drinking plenty of fluids, especially water. Implementing lifestyle changes, such as reducing intake of caffeine and avoiding use of alcohol and tobacco, also help relieve dry mouth. However, chronic dry mouth may be a symptom of an illness, such as diabetes, that requires medical treatment.

In addition to dry mouth, a patient may experience other symptoms that may help physicians determine the cause of xerostomia. These include dysphagia (difficulty swallowing), sore throat, bad breath and headache.

It is recommended that patients contact a physician if they have prolonged dry mouth, especially if it is accompanied by diarrhea, fever, fatigue or unexplained weight loss. Chronic xerostomia may be a sign of an underlying illness and can result in complications including tooth decay and gum disease.

Many elderly people experience dry mouth. However, xerostomia is not a normal part of aging. Most xerostomia occurring in elderly patients is caused by the use of certain medications. Dry mouth is a common side effect of various drugs including antidiarrheals, antispasmodics and high blood pressure medications.

Other common causes of dry mouth include:

• Loss of fluids from the body (dehydration).
  
  
• Infections (e.g., mumps, parotitis) resulting in inflammation of the salivary glands.
  
  
• Chronic illnesses (e.g., diabetes, sarcoidosis).
  
  
• Abnormal growths (e.g., tumors) in the salivary glands.

In many cases, xerostomia does not require immediate medical care and can be relieved by drinking more fluids or using over-the-counter saliva substitutes. However, if dry mouth persists or worsens after relief attempts, patients should contact a physician to avoid complications such as tooth decay.

Some causes of dry mouth require medical attention and prescription medications. For instance, if the salivary glands are not functioning properly, a physician may prescribe medication that stimulates the glands to produce more saliva. Other causes of dry mouth, such as tumors in the salivary glands, may require surgical treatment.