Recurrent mouth ulcers are usually recurrent aphthous ulcers, this disease is related to dietary habits, mood, vitamin deficiencies, etc., if prolonged recurrent episodes should be recommended to seek timely medical attention. However, other diseases may also have oral ulcers, such as leukemia or cancerous ulcers, need to be vigilant. Recurrent aphthous ulcers are of unknown etiology, and are related to habits such as eating spicy food, irregular work and rest, emotional instability, and less intake of vegetables and fruits, etc. They are periodic, recurrent, and self-limiting, and can generally heal on their own. When mouth ulcers recur, it is necessary to consult a doctor in time and improve the relevant examination. Some other diseases, such as cancerous ulcers, leukemia can also have recurrent ulcers. Patients need to clarify the causes of mouth ulcers. In addition, in daily life, we should have a regular routine, light diet, active exercise, maintain a pleasant mood, enhance immunity, and maintain a healthy body.