If only dry mouth but not thirsty phenomenon occurs, the common reasons are shown as follows: 1. abnormal lifestyle: such as blowing air conditioner to sleep, room dryness leads to excessive water loss, may appear dry mouth but no thirst, only due to local mucous membrane dryness; 2. snoring: patients are mostly accompanied by open mouth breathing, resulting in water loss, causing the above phenomenon; 3. dry syndrome: patients may appear dry mucous membrane parts, such as dry mouth, if If one eats white rice alone, it may be difficult to swallow, or if one eats food such as buns and steamed buns, one must use water to help swallow. In addition, besides dry mouth, patients with dry syndrome often have other dry mucous membrane phenomena at the same time, such as dry eyes, which are manifested as the desire to cry without tears. At the same time, they may also have joint abnormalities, such as joint pain, and blood tests are often indicative of abnormal immune indicators. In short, if the dry mouth phenomenon is more serious and affects life, it is recommended to go to the hospital as soon as possible to find the cause and related treatment with the help of doctors.