Patients are usually relieved of pain on the same day of medication and healed within 1 month. Why does the recurrence of mouth ulcers occur? Its etiology is not very clear, but there are many factors that can directly lead to the occurrence of mouth ulcers: infection by microorganisms such as bacteria and viruses; malnutrition and vitamin deficiency; the influence of digestive system diseases such as inflammation of gastrointestinal ulcers, constipation and diarrhea; micronutrient deficiency, such as iron, folic acid, B12 and zinc deficiency; endocrine disorders; mental and neurological Factors, such as work exhaustion, mental tension fluctuations, neurological dysfunction disorders. Some women develop mouth ulcers around the time of menstruation or menstruation, which can only be temporarily relieved by medication, but still appear as usual in the next month when menstruation occurs, with unbearable pain, accompanied by annoying symptoms such as dry mouth, irritability, irritability and dry stools. Clinical studies have found that the appearance of mouth ulcers during menstruation is mainly due to an increase in the level of progesterone and a decrease in the level of estrogen (progesterone, etc.) in the body.