Bad breath is also known as halitosis, and it is usually caused by unhealthy diet, bad habits, and excessive stomach fire, which can be adjusted by adjusting the diet, improving the living habits, and taking medication. 1. Adjust the diet: If the teenager has bad breath caused by unhealthy diet, long-term intake of fat, sweet and thick food, you can make dietary adjustments. Pay attention to eat a light diet, eat more fresh vegetables and fruits, drink more water, avoid eating greasy cold food and overeating, eat more meals. 2. Improve life habits: If bad habits cause bad breath in teenagers, you can improve life habits to regulate. Adhere to the oral cleaning after meals, avoid the intake of alcohol and tobacco, appropriate exercise, maintain a combination of work and rest, avoid staying up late. 3. taking medication: if the teenager has bad breath caused by excessive stomach fire, you can follow the doctor’s advice to choose to take the ox-huang stomach pills, Huanglian Qingqing tablets, stomach pills and other proprietary Chinese medicines to regulate in order to clear the stomach and remove the fire. Teenagers with bad breath may also be caused by other reasons, if the symptoms are not relieved for a long time, it is recommended to consult a doctor in a timely manner, if you need to use medication, please use medication under the guidance of a professional doctor.