Vaginal bleeding after IUD is a side effect of IUD placement. This type of vaginal bleeding is mainly characterized by prolonged menstrual periods or a small amount of spotting, which usually does not require treatment and will return to normal after 3-6 months. However, a few women may experience heavy bleeding and lower abdominal pain after the IUD is placed, which is not alleviated or disappears after 3-6 months after treatment, which indicates that the IUD is not suitable for them and they need to have it removed. Vaginal bleeding caused by the IUD is mainly due to the localization of the IUD in the uterine cavity, causing inflammatory reactions or abnormal contractions of the uterus, which can cause endometrial blood vessel rupture, and thus bleeding will occur.