The causes of chronic mouth ulcers, namely recurrent aphthous stomatitis or recurrent mouth sores, are complex, and studies have shown that they may be related to genetics, autoimmune deficiencies, and immune disorders, including stress and strain, which can also induce immune disorders that can lead to mouth ulcers. In addition, it may be related to viral infections, nutrient such as B vitamins and trace element deficiencies. Mouth ulcers are divided into local treatment and systemic treatment. Local treatment can use antibacterial drugs including tetracycline and gentamycin, anti-inflammatory drugs including glucocorticoid preparation, etc., and local gargling or plastering for treatment. In addition, if the pain is obvious, you can use some analgesic drugs such as lidocaine, dacronine, etc., can play the role of anesthesia pain; systemic treatment can use drugs to regulate immunity, such as thalidomide, levamisole, etc., but also supplemental vitamins, B vitamins, zinc sulfate, etc., serious mouth ulcers can be a short period of time to take a small oral glucocorticosteroid for treatment.