The first time a child has a period of 7 days, and the amount of menstruation is relatively large is generally normal. Children’s first menstruation, also known as menarche, is a normal physiological phenomenon, the general duration of menstruation is 3 to 7 days, the amount of menstruation in 20 to 60 ml. However, when the beginning of menstruation, the body’s pituitary-ovarian axis function is not yet perfect, there may be menstrual anomalies, such as prolongation of the menstrual cycle, menstruation, menstruation, and so on, is usually the case of the normal situation. When children have their first period, they should pay attention to private hygiene, use sanitary products correctly, avoid strenuous activities, eat more nutritious food, and keep their abdomen warm. If severe menstrual cramps, abnormal menstrual flow or other uncomfortable symptoms occur, it is necessary to consult a doctor in time for treatment.