Irregular menstruation can cause a variety of diseases: 1. If the menstrual flow is heavy, the patient will become anemic, mainly manifesting as some symptoms like dizziness, general weakness and weakness when doing a little thing. 2. If the menstrual flow is scanty, amenorrhea will occur. 3. Prolonged menstruation will cause pelvic inflammatory disease and adnexitis, as the prolonged menstruation in the body will cause the cervical opening to be open all the time, at this time Bacteria can easily enter the uterine cavity from the vagina through the open cervical opening, and then cause inflammation of the pelvis. In addition, if the menstruation is excessive, there will also be PMS, which is mainly manifested by clinical manifestations such as feeling general discomfort, weakness, irritability, and lack of concentration before the menstrual flow.