If the amount of menstruation becomes less after removing the IUD, clinically, we should pay attention to exclude the possibility of the following diseases. Firstly, it is recommended to take a blood test on the second or third day of menstruation to find out whether the endocrine secretion is normal and whether the ovarian function is normal, and then according to the result, if there is any abnormality, appropriate treatment should be given. Secondly, if the endocrine system is normal, we should rule out the possibility that the removal of the IUD has caused adhesions in the uterine cavity, which may lead to a decrease in menstrual flow, and it is best to do an ultrasound to find out the thickness of the uterine lining. If the endometrium is thin, the possibility of incomplete adhesion in the uterine cavity is highly suspected, and if necessary, it can be examined under hysteroscopy, and if there are adhesions, the adherent tissues will be separated, so that the amount of menstruation will be restored to a positive state in the clinic.