Due to individual differences, the amount of menstruation is different for each person. Clinically, if the amount of menstruation is between 35-58 ml per day, it is considered normal. If the menstrual flow is less than 30ml per day, it is clinically abnormal and can be diagnosed as menorrhagia. There are many causes of menorrhagia, such as polycystic ovary syndrome, which can reduce menstrual flow and can prolong the menstrual cycle or even cause amenorrhea. There is also tuberculosis of the endometrium, which may also cause a decrease in menstrual flow. Also, if there is a history of abortion or a history of a clean-out procedure that causes damage to the endometrium, this may also reduce the menstrual flow. This decrease is about one-third less than in previous cases, so it is suspected that the decrease in menstrual flow is caused by uterine adhesions.