There are several causes of bad breath: First, their own gingivitis, stomatitis, can show bad breath, need to consult the local hospital stomatology department. Second, Helicobacter pylori infection, can show the oral odor, bad breath, especially the perfect carbon 13, carbon 14 breath test, DPM greater than 700, easy to appear oral odor, most of the results of the metabolites of H. pylori. Third, from the analysis of traditional Chinese medicine, its own spleen and stomach disharmony, spleen qi deficiency resulting in liver qi stagnation, can be manifested as thick and greasy tongue coating, oral odor, bitter mouth, dry throat and other conditions. It is the result of the disharmony of the spleen and stomach and the upward rebellion of the bile and stomach. When bad breath occurs, it is best to improve gastroscopy to clarify the presence of erosion, gastric ulcer or gastroesophageal reflux disease. It is also necessary to improve the monitoring of H. pylori, and if it is positive, anti-H. pylori medication is needed.