Dry mouth syndrome is not contagious. Dry mouth syndrome is an autoimmune disease, in which the autoimmune system attacks its own normal tissues as foreign enemies, resulting in an autoimmune disease. When you have dry syndrome, the salivary glands in the jaw and face are attacked, fibrosis or atrophy occurs, saliva is no longer secreted, or the amount of saliva secreted is significantly reduced, the oral mucosa will be dry, congested, and even accompanied by pain and burning sensation. In addition, the teeth of the whole mouth may also develop violent caries, and it may also be accompanied by other autoimmune diseases such as dry eyes and finger joint pain. If you have dry syndrome, you should go to the rheumatology department of regular hospital for examination as soon as possible and treat accordingly.