If the performance of dry mouth and bitter mouth at night occurs, it may be caused by oral diseases, indigestion, liver and gallbladder abnormalities, etc., which need to be analyzed specifically. 1. Oral diseases: If there are infections in the patient’s mouth, such as gingivitis and periodontal lesions, there will be dry mouth and bitter mouth. 2. Indigestion: If the patient’s digestive function is affected by overeating and binge eating, the peristaltic movement of the digestive tract is abnormal, which may cause bile reflux and dry mouth and bitterness at night. 3. Liver and gallbladder abnormalities: If the patient has gallstones, bile duct abnormalities or hepatitis and other diseases, may also make bile excretion obstacles, bile reflux, resulting in dry mouth and bitter mouth. If the patient’s dry mouth can not be relieved, it is recommended to go to the hospital in a timely manner, under the guidance of the doctor for treatment, to promote the alleviation of symptoms.