Canker sores are large ulcers that can be caused by a variety of factors: infections, immunity, genetics, and psychiatric factors can all contribute to the development of canker sores. If a parent has frequent mouth sores, the chances of the child developing mouth sores will also increase; low immunity or hyper immunity may lead to the occurrence of mouth sores; in addition, anxiety, staying up all night and other mental factors can also lead to the occurrence of mouth sores. In addition, women may also experience aphthous ulcers during menstruation due to lowered immunity or nervousness. After the occurrence of mouth sores, the general symptomatic treatment, under the guidance of the doctor to use some drugs to promote mucosal healing, such as rehabilitation of new liquid or recombinant bovine alkaline growth factor gel, etc., the effect is very good.