Waking up in the morning with a dry mouth and bitter mouth may be caused by oral problems, or it may be a manifestation of liver and gallbladder diseases, gastrointestinal diseases. 1. Oral problems: If the cleaning of the mouth is not in place, it may cause a variety of oral inflammation, such as gingivitis, periodontitis, mouth ulcers and so on. These may lead to waking up in the morning with a dry and bitter mouth. 2. Liver and gallbladder diseases: Waking up in the morning with a dry mouth is considered to be caused by bile reflux, a variety of hepatitis, gallstones or cholecystitis and other liver and gallbladder diseases may lead to bile stagnation, reflux. 3. Gastrointestinal diseases: If the gastrointestinal function is weak, or accompanied by indigestion, gastritis, gastric ulcer and other gastrointestinal diseases, food fermentation in the intestinal tract will also appear in the performance of dry mouth and bitter mouth. In addition, if you drink less water or long-term smokers can also lead to dry mouth in the morning, if accompanied by other discomforts, we need to be alert to other diseases, it is recommended to consult a doctor in a timely manner.