Because of this, there might not be enough saliva to keep your mouth wet. There are several reasons why these your salivary glands might not work. Side effects of medication. More than 400 medications can cause the salivary glands to make less saliva. As you get older, you tend to take more and more medications such as those for high blood pressure and depression.
Some diseases affect the salivary glands.
The saliva glands can be damaged if they are exposed to radiation during cancer treatment. Drugs used to treat cancer can make the saliva thicker, causing the mouth to feel dry and also causing difficulties in speaking. Injury to the head or neck can damage the nerves that tell salivary glands to make saliva. People with certain disorders, like Alzheimer's disease or those who have suffered a stroke, may not be able to feel wetness in their mouth and complain about a dry mouth. The Mouth's naturally occurring protective system comes from three pairs of salivary glands.