Wake up in the morning mouth is very bitter mainly because of bile reflux, occasionally may be related to overeating, such as frequent consideration with the pyloric relaxation or gallbladder disease. You need to go to the gastroenterology department of the hospital to confirm the diagnosis. Bile reflux into the esophagus and pharynx can lead to a bitter mouth in the morning. If it happens once in a while, it is considered to be related to overeating, alcoholism and other bad habits, and the symptoms can disappear after dietary modification. If often get up in the morning mouth is very bitter, may be suffering from gastric pyloric relaxation, cholecystitis, gallstones and other diseases, and can often be accompanied by gastric distension, abdominal pain, loss of appetite, back of the shoulder gallbladder reflex pain and discomfort and other symptoms. You should consult a doctor in time for gastroscopy, liver and gallbladder ultrasonography, etc. to clarify the cause of the disease and actively treat it. It is recommended to maintain good daily habits, eat a light diet, keep three regular meals, avoid staying up late, quit smoking and drinking.