An epidural steroid injection delivers anti inflammatory medication into the epidural space, the area surrounding the nerve roots as they exit your spine. When a disc herniation or narrowing irritates a nerve root, the inflammation around that nerve is often what turns a mechanical problem into radiating pain down your leg or arm.
Reducing that inflammation at the source is what this injection is for.
What it treats
Epidural steroid injections are most often used for sciatica, herniated or bulging discs, spinal stenosis, and radiating nerve pain in the arm from a neck problem. They are also used for cancer-related pain when a tumor or its treatment is irritating a nerve root.
The common thread is pain that travels. If your pain shoots down a limb along a nerve path, rather than staying local to your back, this is often a reasonable step.
Guided, not blind
The injection is performed under image guidance, using live X-ray or ultrasound. Contrast dye confirms the medication is reaching the intended space before any steroid is delivered.
That guidance matters more than it sounds. The epidural space is small and the target is specific. Doing this under imaging is the difference between medication landing where the problem is and medication landing near it.
Depending on your anatomy and the level being treated, the needle is placed either between the vertebrae from behind or through a small opening at the side where the nerve exits. Dr. Serpa will explain which approach fits your case and why.
What to expect
The procedure itself takes about fifteen to thirty minutes. You lie face down, the skin is numbed, and you are awake throughout, though sedation is available.
You may feel pressure during the injection. Some people notice immediate relief from the local anesthetic, which then wears off over a few hours. The steroid takes longer, typically building over several days.
Plan for someone to drive you home. Expect to take it easy for the rest of the day, then return to normal activity.
How many injections, and how often
Epidural steroid injections are not meant to be an indefinite treatment. They are usually used in a limited series, and there are sensible limits on how often steroids should be given in a year.
The purpose is to reduce inflammation enough that you can do the other things that create durable improvement, physical therapy in particular. An injection that buys you a window to rebuild strength is doing its job.
If injections give only brief relief and the pain keeps returning, that is useful information, and it usually points toward investigating a different source or a different approach.