Recently, there has been a steep increase in the number of patients with mouth ulcers, with several patients waiting in line for treatment. In this regard, mouth ulcers is also a disease, long-term recurrence, untreated mouth ulcers can even lead to cancer, the harm should not be underestimated. Mouth ulcers repeated not healed can cause lesions “initially did not take mouth ulcers seriously, but in the past six months, mouth ulcers recurring, eating pain, talking pain, brushing teeth more pain, especially after the winter, the new ulcer surface a bigger than a big, deeper than once.” The patient told us that he thought of coming to the clinic for examination only after being reminded by his friends and relatives. The danger of mouth ulcers should not be underestimated. Long-term recurrence, does not heal, easy to cause oral leukoplakia-like pathological changes, that is, oral pre-cancerous lesions, to the patient brings great pain and economic burden. Long-term recurrence of oral ulcers will also trigger complications such as leukodystrophy, a disease that occurs in the oral mucosa is a systemic immune system disease that can attack multiple organs of the human body, the patient’s nervous system, the digestive system has a greater harm, such as the treatment is not systematic and timely and can even be life-threatening. Pay attention to recognize the signals of frequent mouth ulcers, timely consultation Most patients can only rely on taking vitamins, using topical sprays or patches to relieve pain during the onset of mouth ulcers, although the symptoms are eliminated at that time, but after a period of time, they will recur again and become more and more serious. Repeated mouth ulcers, pain, ulcer surface is deep, the bottom is mostly white or yellow, can be at the same time in the tongue, mouth and lips, palate, pharynx and other parts of multiple ulcers, most of the ulcers can be improved on their own, but often recurring, severe pain is severe, affecting eating. Some patients in the clinic when the disease has often developed more serious, has invaded the eyes, skin, joints, gastrointestinal tract, and so on, and even lead to blindness, intestinal perforation or death. Pay attention to recognize the frequent signals of mouth ulcers and seek timely medical attention.