What Causes Dry Mouth?
People get dry mouth when the glands in the mouth that make saliva are not working properly. Because of this, there might not be enough saliva to keep your mouth healthy. There are several reasons why these glands, called salivary glands, might not work right.
Medicines and Dry Mouth
More than 400 medicines, including some over-the-counter medications, can cause the salivary glands to make less saliva, or to change the composition of the saliva so that it can't perform the functions it should. As an example, medicines for urinary incontinence, allergies, high blood pressure, and depression often cause dry mouth.
Diseases That Can Cause Dry Mouth
Some diseases can affect the salivary glands. Dry mouth can occur in patients with diabetes. Dry mouth is also the hallmark symptom of the fairly common autoimmune disease Sjögren's syndrome.
Sjögren's syndrome can occur either by itself or with another autoimmune disease like rheumatoid arthritis or lupus. Salivary and tear glands are the major targets of the syndrome and the result is a decrease in production of saliva and tears. The disorder can occur at any age, but the average person with the disorder at the Sjögren's Syndrome Clinic of the National Institute of Dental and Craniofacial Research (NIDCR) is in his or her late 50s. Women with the disorder outnumber men 9 to 1.
Cancer Treatments and Dry Mouth
Certain cancer treatments can affect the salivary glands. Head and neck radiation therapy can cause the glands to produce little or no saliva. Chemotherapy may cause the salivary glands to produce thicker saliva, which makes the mouth feel dry and sticky.
Injury to the head or neck can damage the nerves that tell salivary glands to make saliva.