Bitter mouth after waking up at night can be seen in normal people, may also be cholecystitis, gastroesophageal reflux disease, etc., the patient should consult a doctor in a timely manner, to clarify the cause of treatment. 1. Physiological conditions: often smoking or eating spicy and stimulating food will appear after waking up at night bitter mouth, this kind of people should improve their lifestyle, quit smoking and drinking, eat more fresh fruits and vegetables. 2. Cholecystitis: if the patient always wakes up at night with a bitter mouth and a hidden pain in the right upper abdomen, the pain will be aggravated after eating greasy food, then it should be considered to be caused by cholecystitis, this kind of people should improve their life style, and if necessary, can be carried out under the guidance of the doctor for cholecystectomy. 3. Gastroesophageal Reflux Disease (GERD): Gastric contents reflux into the esophagus caused by dysfunction of the barrier structure at the junction of the esophagus and the stomach, and the patient will wake up with symptoms such as a bitter taste in the mouth, heartburn, belching, and a feeling of a foreign body in the throat, etc. This group of people should avoid going to bed or laying down immediately after eating a full meal and, if necessary, can be treated with drugs such as Mosapride under the guidance of a doctor. It is recommended to consult a doctor in time to identify the cause of the treatment, the use of drugs need to follow the doctor’s instructions.