There are many reasons for recurrent mouth ulcers, which may be related to diet, vitamin deficiency or low immunity. If the ulcers are fixed, it should be considered that they are stimulated by sharp teeth, and prolonged ulcers without healing should also be alerted to oral cancer. Recurrent mouth ulcers may be related to diet, if you often eat some spicy and stimulating food, it is easy to lead to recurrent mouth ulcers. Recurrent mouth ulcers are also related to vitamin deficiency, if the lack of vitamin C or vitamin B, it is also easy to cause mouth ulcers, it is recommended to eat more vegetables and fruits to supplement vitamins. Recurrent mouth ulcers may also be related to low immunity, if the patient’s immunity is low, it is also particularly easy to mouth ulcers, it is recommended to exercise more, do not stay up late. If the pain of mouth ulcers is more serious, you can use lidocaine gel to relieve the symptoms under the guidance of the doctor, and you can also use chlorhexidine gargle to rinse your mouth. Mouth ulcers can also be caused by other reasons, if the position is fixed, long time does not heal, we should go to the hospital in time to check whether the tip of the tooth is too sharp, but also alert to oral cancer caused by ulcers.