The period before menopause is called the perimenopausal period, during which menstrual disorders can occur, mainly characterized by irregular cycles, abnormal menstrual periods and menstrual flow. Perimenopausal period is characterized by menstrual disorders in most women due to sporadic ovulation or anovulation, but the performance of each individual is different. Firstly, irregular menstrual cycle can occur, some women show prolonged menstrual cycle, 2~3 months or even longer time to have a menstrual period, while some women show frequent menstruation, about 20 days or even shorter time to have a menstrual period. Secondly, abnormal menstrual flow may occur. Some women may have dysfunctional uterine bleeding due to prolonged anovulation, which is mainly manifested as heavy vaginal bleeding, with a menstrual flow of more than 80 ml or more, while some women mainly manifested as a sudden decrease in menstrual flow, with no more than 20 ml of menstrual blood each time they have their period. Finally, abnormal menstrual periods may occur, with long periods lasting up to 10 days or more, and short menstrual cycles lasting 1 to 2 days. Perimenopausal menstrual abnormalities can last for several months or years, and the severity of the symptoms varies greatly. Women with obvious symptoms need to have ultrasound and hormone levels checked in a timely manner to rule out other diseases, and follow the doctor’s instructions for reasonable treatment according to their own conditions.