An epidural steroid injection is an injection of local anesthetic and cortico steroid deposited into the epidural space. The epidural space is located in the spine just outside of the sac containing spinal fluid. The goal of an epidural steroid injection is to provide pain relief by reducing the inflammation (swelling) of the nerve roots as they exit the spine. An epidural steroid injection will not correct the pre-existing medical problem (i.e. spinal stenosis, herniated or bulging disc, arthritis, etc.) but may improve the level of pain. It is not unusual for someone to need more than one injection to get long term benefit. The injections are done routinely in a series of three injections about 2 weeks apart if needed. If the pain is improved significantly, no further injection is needed unless the pain begins to come back.