Frequent mouth ulcers may be triggered by external stimuli, mental stress or systemic diseases, which need to be examined in hospital to remove local stimuli and treat diseases. 1. Foreign object irritation. The cause of ulcers is unknown, but may be due to the oral cavity has a sharp tooth tip, root or bad restorations damage to the oral mucosa caused by the need to reduce the oral cavity sharp objects on the mucosal stimulation, grinding teeth or restorations. 2. Mental tension. If you stay up late for a long time, mental stress, anxiety, will often appear mouth ulcers, need to maintain a good mental state, happy mood, regular exercise, improve their immunity. 3. Treatment of diseases. Frequently occurring mouth ulcers may also be digestive diseases, such as stomach ulcers or oral cancer manifestations, need to go to the hospital for examination and treatment of disease. Frequent mouth ulcers are recommended to go to the hospital in time to check the cause of the disease and find out the problem in time.