Constantly drinking water and still having a dry mouth is not considered a problem with the oral system in the first place. The most common clinical cause of this problem is diabetes, and you need to check if you have the typical three symptoms of polyhydramnios, which means drinking more, eating more, urinating more, and losing weight, and the typical diabetes will show the above four symptoms. Diabetes a treatment drug called thirst pills, this drug is the solution to constantly drinking water, the mouth is still very dry a typical name of the drug, so the first thing to consider the problem of diabetes. Secondly, in dentistry, a cause of dry mouth with constant drinking is called Schelgren’s syndrome (also called dry syndrome), which is an autoimmune system disease, related to glandular secretion. Patients with this disease have a significant enlargement of the glands, but the secretion is significantly reduced, and the ability to produce saliva and saliva is significantly reduced. In this case, the patient also has the symptom of constantly drinking water and having a dry mouth, and in general, there are also dry eyes, joint pain in the limbs and other rheumatic immune related manifestations.