Halitosis is resolved by identifying the cause and treating the symptoms. For example, periodontitis, caries, sinusitis, etc. can lead to bad breath, mainly through medication, surgical treatment. The treatment effect varies from person to person. 1. Periodontitis is a chronic inflammation that invades the gums and periodontal tissues, and periodontal pus overflow is often accompanied by bad breath. The basic treatment for periodontitis is scaling. If there is a periodontal abscess, it can be incised and drained. At the same time, oral medication such as metronidazole can be taken. 2. The residual food debris on the surface during caries will react with oral bacteria, which will lead to the production of abnormal odor and cause bad breath. Shallow caries without cavities can be controlled with medications, including fluoride. The teeth that have formed cavities need to be filled and restored, and composite resin filling can be used. If the cavity is deep enough to damage the nerve and cause pulpitis, root canal treatment is needed. 3. Sinusitis is an infectious disease of the sinuses caused by bacteria or fungi, which produces purulent secretions and leads to bad breath. Both acute and chronic sinusitis can be treated with medication. The infection is usually controlled with adequate amounts of antibiotics, commonly used drugs include penicillin and other antibiotics. Chronic sinusitis can be treated with nasal irrigation, sinus puncture irrigation or surgery. If you find that the symptoms of bad breath worsen, you should seek medical advice and treatment under the guidance of a doctor to avoid delaying the condition. Drink more water on weekdays, pay attention to avoid drinking coffee, tea and other beverages, and maintain oral hygiene.