Mouth ulcers not only cause unbearable pain to the organism, but also interfere with normal study and work. The organism is prone to suffer from mouth ulcers due to vitamin deficiency, low immunity and menopause. Patients with mouth ulcers are recommended to eat more foods containing zinc, such as walnuts, peanuts, melon seeds, eggs, meat, animal liver and so on. Because the food containing zinc is good for the healing of mouth ulcer wound. It is also recommended to eat more foods rich in vitamins: vitamin B1, vitamin B2, and vitamin C. Common foods are fresh fruits and vegetables, such as carrots, cabbage, apples, bananas, persimmons, etc. If the symptoms of mouth ulcers are relatively mild, the ulcer surface can be healed quickly by eating these foods, but if the mouth ulcer surface is large, it is recommended to take medication. Yunnan Baiyao is a commonly used drug that is usually applied externally to the mouth ulcer and can be cured in about three days. Vitamin C can also be powdered and applied to the ulcer, but this method is only suitable for patients with small ulcers. When the organism has a mouth ulcer, it is recommended to take the appropriate method according to the size of the ulcer surface, which can be relieved by dietary attention when the symptoms are relatively mild. Generally speaking, mouth ulcers can heal by themselves in a week or so. If there are ulcers in the mouth that do not heal by themselves for more than 2 weeks, it is necessary to visit a regular oral medical institution to investigate whether they are cancerous or not.