My doctor has recommended an epidural steroid injection for my back pain. What is this?

Sometimes, doctors call this a “nerve block.” Cortisone, along with an anesthetic agent such as lidocaine, is injected into the epidural space. This is the space just outside the spinal cord. Here, the nerve root leaves the spinal cord and travels down the low back to the legs.

The steroid acts as an antiinflammatory to reduce swelling. Lidocaine or some other numbing agent stops the pain.