Oral ulcers are not a serious illness, but they are really fatal. Once you have oral ulcers, you can’t eat it. It smells bad, and even drinking saliva is sour. Oral ulcers are recurrent, because oral ulcers themselves are not cured like disinfection, but grow on their own as the oral mucosa renews every 4-14 days. So once there is a suitable incentive, oral ulcers will make a comeback. The etiology and pathogenesis of oral ulcers are still a mystery, but do not add vitamins indiscriminately, and do not take medicine to “lower fire”. In most cases, oral ulcers are caused by poor oral hygiene.  . What we need to do is to reduce oral irritation, rinse mouth after meal, and remove residual food residue. If it is really painful, you can consider using drugs to help relieve it. Although oral ulcers will heal on their own, they are relatively large and recurrent and the pain is unbearable. It is recommended to go to the hospital to diagnose whether it is ordinary oral ulcers or other oral diseases.