Halitosis may be caused by physiological bad breath or pathological bad breath, and different causes need to be treated to eliminate the root cause. 1. Physiological bad breath: physiological bad breath may be caused by irritating foods, drugs or poor oral hygiene habits. Patients can gargle after meals, strengthen oral hygiene, brush teeth every day, use mouthwash containing antibacterial ingredients as prescribed by the doctor, and drink more water. 2. Pathological bad breath: pathological bad breath may be caused by gingivitis, periodontitis, chronic gastritis and other diseases. Patients can take medications such as amoxicillin, ceftriaxone sodium, omeprazole, etc., or ultrasonic scaling under the guidance of a doctor. Patients are advised to keep their mouths clean and eat less spicy and irritating food. Eat more vegetables and fruits such as celery, spinach and apple. Patients should go to the hospital to confirm the cause of the disease and then symptomatic treatment. Please do not self-medicate to produce adverse reactions.