There is no such thing as a permanent solution to bad breath. The causes of bad breath mainly include poor oral hygiene, oral diseases, oral adjacent tissue diseases, internal diseases and so on. 1. Poor oral hygiene: If you do not pay attention to oral hygiene will lead to a variety of food residues stay in the mouth for a long time, gradually corruption, causing the accumulation of bacterial metabolites, resulting in an unpleasant sour taste. Therefore, we must do after meals rinse, morning and evening brushing, usually available mouthwash mouthwash, or breath freshener spray to keep the mouth clean. 2. Oral disease: If there are cavities in the mouth, tartar, or lesions of the oral mucosa, such as thrush, etc., may cause bad breath. Actively treat the primary disease to remove bad breath, such as filling treatment for caries, scaling and scraping to remove tartar. 3. Diseases of the tissues adjacent to the oral cavity: such as purulent tonsillitis, chronic maxillary sinusitis, atrophic rhinitis, etc., can produce purulent secretions and emit a foul odor, can be prescribed by the application of cephalosporin anti-inflammatory drugs, after the inflammation is dissipated, the halitosis will also disappear. 4. Internal disease: if the patient dyspepsia, constipation or gastrointestinal disease patients, can often appear bad breath. At this time, you can follow the doctor’s instructions to take oral domperidone and other gastrointestinal stimulants to relieve symptoms, to improve bad breath. Usually pay attention not to eat food containing odor, such as onions and garlic, and pay attention to prevent other spicy and stimulating food. If the long-term bad breath patients, it is recommended to consult a doctor in time to identify the cause of the disease, by the doctor to clarify the cause of the disease, to give targeted treatment.