If bad breath is caused by poor oral hygiene, you need to brush your teeth diligently, and if it is caused by dental disease or gastrointestinal disease, you should have targeted treatment. Bad breath can be caused by a variety of reasons, should be clear about the cause. Oral odor can be caused by poor hygiene habits, usually should be diligent brushing, regular dental cleaning. If it is caused by dental caries, fillings and root canal treatment are needed. If it is caused by periodontitis, periodontal treatment such as scaling and scraping is needed. If it is caused by gastrointestinal diseases such as Helicobacter pylori infection, it can be treated with clarithromycin, metronidazole, omeprazole, bismuth pectin, and so on. If the mouth odor is obvious, go to the hospital in time for examination, and follow the doctor’s instructions when using the above drugs.