Early symptoms of cancerous ulcers usually include duration, pain, general condition, dysfunction and so on. 1. Duration: usually recurrent ulcers can be healed in one to two weeks, if the ulcers last for a long time, even more than one month and still not healed, patients should be alert to the possibility of malignant tumor. 2. Pain: usually, there is no obvious pain or mild pain and discomfort in the early stage of ulcers, if the patient has obvious pain after ulcers, it is because with the further invasion of nerves by the tumor, which leads to obvious pain. 3. Systemic condition: usually, ulcers caused by malignant oral cancer will show symptoms such as swollen lymph nodes and lymph node adhesion. 4. Functional disorder: if the tumor invades the opening and closing muscles or temporomandibular joint, the opening and closing movement will be restricted. If patients have the above symptoms, it is recommended to seek medical treatment in time and carry out standardized treatment under the guidance of doctors.