There will be a layer of white pseudomembrane on the ulcer, in fact, is the normal oral tissue necrosis left on it, try not to erase it by themselves, although it is already a layer of necrotic tissue, but the ulcer plays a protective role. If erased, it is likely to lead to fresh wounds exposed to the oral environment, it is easy to occur ulcer infection. If the ulcer is not treated, it will generally heal itself in 7-12 days, so patients do not have to worry too much and try not to touch it with their hands, because hands are bacterial. Ulcers often flare up, mainly because the patient may be more nervous, or work and rest is not regular, resulting in immune deficiencies, so it is easy to induce recurrent mouth ulcers. Patients should correct the bad work and rest time, face life with a positive attitude, improve the psychological situation, mouth ulcers will naturally heal.