There are several cases of bitter mouth: 1, gallbladder diseases, such as gallstones, cholecystitis, etc. These diseases will lead to poor gallbladder function, bile drainage will become abnormal, which will easily lead to bitter mouth. 2, gastrointestinal diseases, unhealthy diet can easily lead to indigestion, digestive diseases, such as gastritis, enteritis, gastric ulcer, etc., which will lead to abdominal flatulence, the gas in the stomach and intestines can not be smoothly expelled, and then constantly upward will lead to bitter mouth. 3, kidney disease, such as kidney stones, renal insufficiency, nephritis, etc. also easy to cause the mouth odor, the symptoms of bitter mouth. 4, oral disease, if the daily check and brush teeth and mouth bitter symptoms, may be the gingivitis. 5, mental factors, prolonged mental stress will affect the gastrointestinal health, the body’s The metabolism of the body will have problems, and there may be bitterness in the mouth.