An epidural steroid injection (ESI) is a minimally invasive procedure that can help relieve neck, arm, back, and leg pain caused by inflamed spinal nerves. ESI may be performed to relieve pain caused by spinal stenosis, spondylolysis, or disc herniation. Medicines are delivered to the spinal nerve through the epidural space, the area between the protective covering of the spinal nerves and bony vertebrae. Pain relief may last for several days or even years. The goal is to reduce pain so that you may resume normal activities and a physical therapy program.

A steroid injection includes both a corticosteroid (e.g., triamcinolone, methyl-prednisolone, dexamethasone) and an anesthetic numbing agent (e.g., lidocaine or bupivacaine). The drugs are delivered into the epidural space of the spine, which is the area between the protective covering (dura) of the spinal cord and nerves and the bony vertebrae.