There are many reasons for sweet mouth, which may be caused by improper diet, gastroesophageal reflux, diabetes and other diseases. 1. Improper diet, if you often do not pay attention to your diet in your normal life, and eat foods containing more sugar, it may lead to sweet mouth symptoms. 2. Gastroesophageal reflux (GERD). If GERD occurs, sweet mouth symptoms may occur when food is not digested and absorbed after intake and refluxed into the mouth. 3. Diabetes mellitus, patients with diabetes mellitus, due to elevated blood glucose levels in the body, the body is unable to properly utilize the glucose in the blood, and may be secreted into the mouth through saliva, so sweet mouth symptoms may occur. If there are obvious symptoms of sweet mouth, you need to consult a doctor in time for examination and treatment.