The common causes of morning mouth bitterness are as follows: 1. Chinese medicine believes that mouth bitterness is related to dampness and heat, mainly due to long-term dietary disorder, over-eating fatty, sweet and thick tastes or irregular life, smoking and drinking leading to the loss of health of the spleen and stomach, then causing the abnormal transport of water and dampness, water and dampness within the stop, or emotional discomfort, liver and gallbladder draining abnormalities leading to the blockage of the middle jiao qi, day long depression and heat caused by mouth bitterness; 2. Bitterness in the mouth is caused by a prolonged diet of spicy and stimulating hot and dry products, resulting in spleen and stomach heat, and due to the medical origin of the initial use of too bitter and cold medicine, which does not give the evil a way out, resulting in the internal heat of the evil, causing recurrent bitterness in the mouth, which is not cured for a long time, and Western medicine believes that there is an infection or blockage in the liver and gallbladder, causing the abnormal excretion of bile and bitterness in the mouth; 3. 3, poor gastric power, obstructed gastric emptying, indigestion, bile reflux, etc., and oral diseases, chronic stomatitis, gingivitis caused by bitter mouth; 4, mental bitterness, due to long-term mental stress caused by bitter mouth, and chronic diseases such as diabetes caused by bitter mouth.