From the perspective of traditional Chinese medicine, on one hand, the bitter mouth is caused by the evil in Shaoyang, which can be relieved by Xiao Chaihu Tang; on the other hand, it is caused by dampness-heat of the liver and gallbladder (dampness-heat evils are accumulated in the liver and gallbladder), which can be relieved by Longguan Diarrhea of the Liver Tang. 1. Evil in Shaoyang: Xiao Chaihu Tang is from “The Treatise on Typhoid Fever”, which can not only relieve the evil of Shaoyang, but also clear the liver fire and lower the stomach qi. In this formula, Chaihu can relieve the liver and relieve depression (treating depression by unblocking the liver’s qi), dispersing the depressed qi; and Scutellaria baicalensis, which is a bitter, cold and diarrheal agent, clears the fire of the liver and gallbladder, thus improving the bitterness of the mouth. The contraindications and adverse reactions of this formula are not clear. 2. Liver and gallbladder dampness and heat: Longdian Diarrhea Liver Soup is from “Collection and Interpretation of Medical Formulas”, which contains gentian herb, psyllium, scutellaria, angelica, gardenia, chaihu, raw huangdi, zejiao, chaihu, moutong, raw licorice and other traditional Chinese medicines, which can clear liver and gallbladder dampness and heat, so as to improve the manifestation of bitter taste of the mouth. The Chinese herbal medicines in this formula are mostly bitter and cold, easily injuring the spleen and stomach, so they should not be used for people with evidence of deficiency of spleen and stomach (spleen and stomach weak and cold) and deficiency of yin and hyperactivity of yang (yin-liquid deficiency and hyperactivity of yang), and the contraindications are not yet clear. When the patient appears bitter mouth performance, it is recommended to go to the regular hospital in a timely manner, under the guidance of a professional doctor for medication.