How painful is an IUD insertion?

Understanding the Pain of IUD Insertion

Doctors perform the insertion of the IUD by passing it through the cervix and positioning it inside the uterus. During this procedure, patients may feel pain that can vary from mild discomfort to intense cramping. According to McEvoy, "The main cause of the pain is the IUD entering the uterine cavity, which leads to contractions in the uterus."