Bad breath brings social troubles to many people and has a great impact on the psyche, bad breath does not dare to talk to people and gives others a bad impression. The symptoms of halitosis are related to oral diseases, sinusitis and gastroenteritis, etc. There are several reasons: 1, poor oral hygiene, not brushing, not rinsing or not carefully brushing, the accumulation of food residues in the mouth, fermentation and corruption under the action of bacteria, producing amines, emitting rotten odor. 2, gingivitis, periodontitis, so that the soft tissues of the mouth in a long-term inflammatory state, abscess, bleeding, ulceration, also easy to produce corrupt Bad breath. 3, dental hard tissue lesions, that is, dental caries, because of the presence of decay in the decayed teeth, will cause bad breath. 4, physical diseases can cause bad breath, such as indigestion, gastritis, etc. can cause bad breath, bad breath, bitter mouth, etc.