Dry mouth (also called xerostomia) is what happens when saliva flow is reduced or absent. It may be a symptom of your medical condition or medications. It is not a disease and is quite common. While it may seem like a minor condition, moist saliva is critical to the health of the mouth and has protective benefits for oral tissues and to prevent tooth decay. Extreme dry mouth may contribute to permanent mouth or throat disorders. First, let’s talk about why saliva is important. Saliva aids in killing harmful bacteria, and keeps your mouth moist, which in turn helps to prevent cavities and strengthens your teeth by restoring important minerals. Dry mouth is a common condition. Some of the most frequent causes are from certain prescription medications such as antihistamines, diuretics, antihypertensives and sedatives. Malfunctions in the salivary glands, certain autoimmune disorders (such as Sjogren’s syndrome), fear, anxiety, and radiation or chemotherapy can contribute to dry mouth. Diabetes, dehydration, chewing tobacco, hormonal imbalances, mouth breathing and sleep apnea can cause dry mouth.