Don’t treat bad breath as a disease, the World Health Organization has documented bad breath as a disease. 1999 International Halitosis Forum 3 meeting determined the international classification of bad breath: including true halitosis, pseudohalitosis and halitophobia. True halitosis is a distinct odor from the patient’s mouth that can be felt by others and is subdivided into physiological and pathological halitosis. The treatment of halitosis is more difficult, mainly etiological treatment. Etiology: 1, oral diseases such as dental caries, periodontal disease, dry mouth, denture unclean, etc. 2, nasopharyngeal diseases such as sinusitis, tonsillitis, laryngitis, etc. 3, systemic diseases such as gastrointestinal diseases, liver disease, diabetes, bronchopulmonary diseases, nephritis, heart disease, malignant tumors, etc. 4, taking certain drugs or eating leeks, onions, garlic, broccoli and other foods containing sulfur. 5, mental factors Some patients originally did not have bad breath, but by the attitude of others presumed to be false halitosis. Some are fear of halitosis caused by psychological stress and mental hypersensitivity. 6, Chinese medicine believes that the etiology of halitosis are: stomach fire on inflammation, liver fire offending the stomach, food stagnation stop stomach, phlegm and heat congestion lung. Treatment: 1, treatment of the original disease Active treatment of oral diseases, nasopharyngeal diseases and systemic diseases. 2, pay attention to oral hygiene Insist on brushing teeth after three meals, use tongue cleaner, use mouthwash. 3.Eat more fruits and vegetables, drink more yogurt, and eat less sulfur-containing drugs and foods. 4.Take Chinese herbal medicine for evidence-based treatment, use Liang Di San, Yi Yao San, Bao He Wan, Diarrhea Bai San, Diarrhea Heart Soup combined with Bai Hu Tang, etc. 5.Pseudostomatitis requires psychological treatment.