Bitterness in the mouth refers to a bitter taste in the mouth. It is mostly seen in acute inflammation, mainly in liver and biliary inflammation, which is often related to the metabolism of bile sweat. 1, mental mouth bitterness, modern work and life pressure, so that a large number of people have long-term work and mental stress, irregular life, lack of sleep and rest, lack of exercise, etc., causing mouth bitterness; excessive smoking, alcohol abuse, snoring, open mouth sleep, etc. also prone to dry mouth, mouth bitterness. 2, oral inflammation, if there is gingivitis, gum bleeding and other oral diseases, is a common cause of bitter mouth. 3, stomach heat and bitter mouth, esophagitis, chronic gastritis, due to poor gastric power, the presence of bile reflux, accompanied by heartburn and other symptoms, may also cause bitter mouth. If the diet is improper, its gastrointestinal function is sluggish, and the food eaten stays in the stomach and intestines for too long, it is very easy to produce damp heat, which will cause bitterness in the mouth. The consumption of too much spicy food can also cause bitterness in the mouth. 4, some chronic diseases, diabetes often accompanied by bitter mouth; In addition, cancer patients because of the sweet taste valve increased, bitter taste valve reduced, will also feel bitter mouth, should be vigilant. 5, liver and gallbladder diseases, such as bitter mouth in the morning, is mostly caused by damp heat. Bitterness in the mouth due to damp heat in the liver and gallbladder may be caused by inflammation in the liver and gallbladder. Such as when the liver or gallbladder inflammation, bile excretion malfunction leads to bitter mouth.