Recurrent oral ulcer is a limited ulcerative injury of the oral mucosa characterized by periodic recurrence, which can heal spontaneously and can occur in any part of the oral mucosa. It is characterized by single or multiple round or oval ulcers of different sizes on the mucous membrane of the lips, cheeks, soft palate or gums of the mouth, covered with gray or yellow pseudomembrane, with a central depression, clear borders, red and slightly swollen surrounding mucosa, and local burning pain. The recurrence of oral ulcers is medically known as “recurrent oral ulcers”. The length of recurrence is closely related to the length of history of oral ulcers, and when the history is short, it can develop once a few months or a year; when the history is long, it can develop once a month, or alternate old and new lesions of oral ulcers. I. Commonly used treatment methods Generally, patients are relieved of pain on the day of medication and healed within one month. Although there are many treatments for oral ulcers, they are basically symptomatic treatments, aiming mainly to relieve pain or reduce the number of recurrences, but cannot completely control recurrence, so prevention of the disease is especially important. You should pay attention to keep your mouth clean, rinse your mouth with light salt water, quit smoking and drinking, live a regular life and ensure sufficient sleep. Adhere to physical exercise, eat a light diet, eat more vegetables and fruits, eat less spicy, thick-tasting stimulating food, and keep the bowels unobstructed. Women should pay attention to rest before and after their periods, keep a happy mood, avoid excessive fatigue, eat a light diet, eat more fruits and fresh vegetables, drink more water, etc., to reduce the chances of mouth sores. It should be reminded that ulcers in the mouth that do not heal over time may become cancerous over time due to the constant stimulation of chewing and talking. Especially in those parts of the mouth that are in contact with teeth, such as the presence of remaining broken teeth that have not been removed, or wearing dentures that are not properly made, their sharp edges constantly stimulate and scratch the mucous membrane, resulting in ulcers, which will not heal but will get worse if the stimulating factors are not removed. This kind of ulcer that does not heal over time may also be a precancerous lesion that is highly susceptible to cancer. If you often suffer from mouth ulcers, you need to pay attention to the above-mentioned issues. Specific measures for prevention 1. Pay attention to oral hygiene, avoid damage to the oral mucosa, avoid spicy food and local stimulation. 2, keep a relaxed mood, optimistic and cheerful, avoid things and anxious. 3.Ensure sufficient sleep time and avoid over fatigue. 4, pay attention to regularity of life and balanced nutrition, develop certain bowel habits to prevent constipation.