The normal menstrual cycle is around 28 days, and the week before and after is within the normal range, that is, 21-35 days are normal. The duration of menstruation is 3-7 days, less than 3 days is called short menstruation and more than 7 days is called prolonged menstruation. Menstruation is a process that occurs when the endometrium changes from the proliferative phase to the secretory phase and finally shedding and bleeding as the follicles mature and ovulate, and as the ovaries secrete estrogen and progesterone in a cyclical manner. Menstruation is regular and is accompanied by regular vaginal bleeding as a result of normal ovulation. Menstruation is mainly influenced by the reproductive endocrine axis. In addition to this, external factors such as weather changes, psychological conditions, and short-term weight gain or loss may also affect menstruation.