Mouth ulcers are closely related to genetics but cannot be generalized due to individual variability. Mouth ulcers are a common disease of the oral mucosa, a variety of factors lead to the formation of painful ulcers on the oral mucosa. Mouth ulcers are closely related to genetics, and studies have shown that there is a certain genetic predisposition to mouth ulcers. However, due to different personal circumstances, not all patients’ mouth ulcers are caused by heredity, and their etiology can be triggered by a variety of factors. When the patient’s immunity is low, the body can be attacked by pathogens, easy to induce mouth ulcers. Or it may be triggered by mental stress, improper diet, physical trauma and other factors. Mouth ulcers are usually found on the mucous membranes of the lips, cheeks, soft palate and other parts of the mouth, and are characterized by round or oval sunken ulcers surrounded by slight redness and swelling, and accompanied by obvious pain. Once diagnosed with mouth ulcers, patients need to actively cooperate with doctors to take relevant treatment measures to avoid delaying the condition.