Dry mouth or xerostomia refers to a condition in which the salivary glands in your mouth don't make enough saliva to keep your mouth wet. Saliva helps prevent tooth decay by neutralizing acids produced by bacteria and limiting bacterial growth. It rinses and removes unwanted leftovers from your mouth, helps break down food when you eat and provides disease-fighting substances to help prevent cavities and infections. Saliva also enhances your ability to taste and makes it easier to chew and swallow. In addition, enzymes in saliva aid in digestion. If you don’t make enough saliva, one sign may be halitosis.
Dry mouth can be caused by medications, certain medical conditions, alcohol use, tobacco use or excessive caffeine. Dry mouth is often due to aging, the side effect of certain medications or as a result of radiation therapy for cancer.