An IUD is a small plastic and copper device that is put into your uterus (womb). It has one or two threads on the end. These thin threads hang through the opening at the entrance of your uterus (cervix) into the top of your vagina.
There are different types and sizes of IUD to suit different women. An IUD can stay in for 5–10 years, depending on the type. If you are aged 40 or older when the IUD is fitted, it can be left in until the menopause. It should only be fitted by a trained doctor or nurse. An IUD is sometimes called a coil.