Mouth ulcers that have been bad may be caused by factors such as living habits, such as irregular living habits, having bad oral habits or eating habits, etc. The repeated irritation of mucous membrane by residual teeth and dentures in the mouth may cause mouth ulcers that have been bad. If it is caused by the above-mentioned bad factors, you need to improve your diet, such as eating less sweet and spicy stimulating food, relax, pay attention to oral hygiene, smoke less and drink less, remove the irritating factors of oral mucosa, and also use drugs such as lidocaine gel and ice borax to stop the pain and promote the healing of ulcers. However, if the mouth ulcer remains bad after the above treatment, it is necessary to seek medical examination to rule out whether it is a concomitant symptom of other diseases. Usually need to treat the original disease, after the original disease is cured, the symptoms of mouth ulcers can also be relieved or restored. 1, recurrent aphthous ulcers: mouth ulcers have been bad may be recurrent aphthous ulcers. The cause of this disease is more complex, and the causative factors need to be clarified after the diagnosis and the causes eliminated. There is no specific medicine to cure recurrent aphthous ulcers. Lidocaine gel and ice borax can be used to relieve pain and promote the healing of the ulcer surface. Some patients also have relief with vitamin B and vitamin C. In addition, treatment can be carried out through herbal tonics on the basis of identification and treatment by herbalists, which can also be effective. 2. Infectious lesions: such as oral herpes virus infection, oral fungal infection, etc. The lesions may be similar to ulcers, so treatment according to ulcers has not been good, laboratory tests can be done to clarify the nature of the lesions and treat accordingly according to the test results, and if the test reveals herpes virus infection. If it is found to be herpes virus infection, it should be treated with antiviral drugs such as ribavirin and acyclovir; if it is fungal infection, it needs to take drugs such as mycophenolate and amphotericin B to control the infection; 3, cancer: if the oral ulcer is not good all the time, there is a small possibility that it is oral mucosa cancer. Once it is found to be cancerous, the local lesion can be removed surgically and the progress of the disease can be controlled by radiotherapy.