What are Epidural Steroid Injections?

Epidural corticosteroid injections place medication directly around a pinched nerve as it exits the spine within the epidural space. The epidural space is between the bones and discs of the spine, and the nerves and spinal cord. This is the space into which disc tissue can herniate and cause pressure and inflammation around spinal nerves.

what conditions can epidural steroid injections help with?

Epidural steroid injections are commonly used to treat back pain caused by a herniated disc (slipped disc), lumbar radiculopathy, spinal stenosis or sciatica. Corticosteroids are strong anti-inflammatory medications and, when placed into the epidural space, can significantly reduce inflammation around an irritated nerve that is causing back and leg pain and discomfort.

how does it work?

Epidural steroid injections work by delivering a potent anti-inflammatory to the site of nerve impingement in the spine. Injected medications may include steroids, local anesthetics, and saline, and they can vary in volume and concentration on an individual basis.

Three routes may be used for epidural injections in the lumbosacral spine:

  • caudal
  • interlaminar (also known as translaminar)
  • transforaminal

Your physician will choose which method is right for you based on your diagnosis and if you have had any prior spine surgeries.

  • A caudal injection is the least complicated way to access the epidural space but is also the least specific. It can be useful if multiple areas of the spine are involved or if post-surgical changes prevent other approaches.
  • An interlaminar (or translaminar) injection delivers the medication directly into the epidural space at the affected level, can be targeted to one side or the other, and can treat multiple levels at once.
  • A transforaminal injection delivers the medication to the area where the specific affected nerve root exits the spine and is compressed by a disc herniation. It is the usual first choice approach for an epidural injection.


Common side effects include mild injection site pain, temporary worsening of usual pain, flushing, insomnia, or increased blood sugar. These are usually self-limited and resolve within one to three days. A less common side effect is headache.