Bad breath may occur after the appearance of periodontitis. 1. Periodontitis is mainly inflammatory changes in the tissues around the teeth, there may be more inflammatory secretions oozing out, and there are also a large number of bacteria, so there may be bad breath symptoms. 2. general periodontitis bad breath need to actively seek medical examination, you can choose to carry out systematic periodontal treatment such as cleaning, scraping, but also can use 3% hydrogen peroxide or saline for local cleaning, but also under the guidance of the doctor to use metronidazole, ornidazole and other medications, can effectively remove the periodontitis, to avoid the worsening of the symptoms of halitosis. Usually need to pay attention to personal oral hygiene, diligent brushing and rinsing, but also need to maintain a light diet, eat less sugary or salty food, the use of drugs need to follow the doctor’s instructions.