DefinitionAn epidural steroid injection (ESI) is the delivery of powerful anti-inflammatory medicine directly into the space outside of the sac of fluid around your spinal cord. This area is called the epidural space.It is not the same as an epidural anesthesia given prior to childbirth.Alternative NamesESI; Spinal injection for Back pain; Back pain injectionDescriptionYou will be asked to change into a gown and then lie face down on an x-ray table with a pillow under your stomach. If this position causes pain, you will be asked to either sit up or lie on your side while in a curled position.The health care provider cleans the area of your back where the needle will be inserted, and may use medicine to numb the area. You may be given medicine to help you relax.Most of the time, your doctor will use an x-ray machine that produces real-time pictures to help guide the needle to the correct spot in your lower back. The doctor injects a mixture of steroid and numbing medicines into the area. This medicine decreases swelling and pressure on the larger nerves around your spine and helps relieve pain.You may feel some pressure during the injection, but most of the time the procedure is not painful.You will be watched for 15 to 20 minutes after the injection before going home.IndicationsYour doctor may recommend an epidural spinal injection if you have pain that spreads from the lower spine to the hips or down the leg (radicular low back pain). Such pain is caused by pressure on a nerve as it leaves the spine, most often due to a bulging disc.The injections are rarely used unless your pain has not improved with medicines, physical therapy, and other nonsurgical treatments.RisksEpidural injections are generally safe. Possible complications may include:Dizziness, headache, or feeling sick to your stomach may occur but most of the time are mild.Nerve root damage with increase pain down your legInfection in or around your spine (meningitis or abscess)Allergic reaction to the medicine usedBleeding around the spinal column (hematoma)Talk to your doctor about your risk of complications.Having these injections too often may weaken the bones of your spine or nearby muscles. Receiving higher doses of the steroids in the injections may also cause these problems. As a result, most doctors limit patients to two or three injections per year.Expectations after surgeryEpidural steroid injections provide short-term pain relief at least half of the people who receive them. Symptoms may remain better for weeks to months, but rarely up to a year.The procedure does not cure the cause of your back pain. You will need to continue back exercises and other treatments.Before You Have the ProcedureYour doctor will most likely have ordered an MRI scan of the back before this procedure. This helps your doctor determine the area to be treated.Before your procedure, tell your doctor or nurse:If you are pregnant or might be pregnantWhat medicines you are taking, including herbs, supplements, and other drugs you bought without a prescriptionYou may be told to stop taking medicines that make it hard for your blood to clot for several days before the test. This may include aspirin, ibuprofen (Advil, Motrin), clopidogrel (Plavix), warfarin (Coumadin), naproxen (Aleve, Naprosyn), and heparin.Always check with your doctor before stopping any medications.ConvalescenceYou may feel some discomfort in the area where the needle. This should only last a few hours.Your doctor may ask you to rest for the remainder of the day.Your pain may become worse for 2 to 3 days after the injection before it begins to improve. The steroids usually takes 2-3 days to work.If you receive medicines to make you sleepy, you must arrange for someone to drive you home.ReferencesChou R, Loeser JD, Owens DK, Rosenquist RW, et al; American Pain Society Low Back Pain Guideline Panel. Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society. Spine. 2009;34(10):1066-77.Staal JB, de Bie RA, de Vet HC, et al. Injection therapy for subacute and chronic low back pain: an updated Cochrane review. Spine. 2009;34(1):49-59. Review.Jegede KA, Ndu A, Grauer JN. Contemporary management of symptomatic lumbar disc herniations. Orthop Clin North Am. 2010 Apr;41(2):217-24.Reviewed ByReview Date: 06/04/2011David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., and C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery.