Halitosis can be seen in oral diseases, constipation, gastric dilatation, usually can eat less greasy stimulating food, but the main thing is to actively treat the original disease. 1. Oral diseases: such as periodontitis, gingivitis, etc., according to the different conditions, scaling, scraping, etc., can follow the doctor’s instructions to use antibacterial drugs such as metronidazole, amoxicillin and so on. At the same time, pay attention to maintain oral hygiene, gargle after meals, brush your teeth every morning and evening. 2. Constipation: follow the doctor’s instructions to use drugs to improve constipation, such as lactulose, micro-ecological agents double gas triple live bacteria, acetic acid bacteria tablets and so on. At the same time, pay attention to increase the dietary fiber-rich fresh fruits and vegetables. 3. Helicobacter pylori infection: need to use antibiotics, proton pump inhibitors and bismuth under the guidance of a doctor for Helicobacter pylori eradication. Such as the use of antibiotics amoxicillin, clarithromycin, proton pump inhibitor omeprazole, gastric mucosa protector bismuth potassium citrate. Do not eat irritating food, greasy food, eat more fruits or drink water when bad breath occurs, but at the same time, you need to consult a doctor in time to clarify the cause of the disease, and take appropriate treatment for the cause under the guidance of a professional doctor. Drugs should be used under the guidance of a physician.