A spinal injection is a procedure that delivers anti-inflammatory and pain-relieving medication directly to a specific area of the spine. It’s one of the most common nonsurgical treatments for back and neck pain, used both to relieve pain and to help pinpoint exactly where pain is coming from. Most spinal injections combine a steroid to reduce inflammation with a local anesthetic for immediate numbing, and they’re performed using real-time X-ray imaging to guide the needle precisely into place.
Types of Spinal Injections
Not all spinal injections go to the same spot or treat the same problem. The type you receive depends on where your pain originates and what’s causing it.
Epidural steroid injections are the most widely used. The needle is placed into the epidural space, a thin area just outside the membrane that surrounds the spinal cord. These treat pain that starts in the spine and radiates into an arm or leg, often from a herniated disc or spinal stenosis. Inflammatory compounds tend to concentrate near damaged disc material, and the steroid works by interrupting that inflammatory cycle.
Facet joint injections target the small joints that connect each vertebra along the back of the spine. These joints can become painful from arthritis or injury. The injection goes directly into or around the joint, and if it relieves your pain, it confirms the facet joint is the source.
Trigger point injections address tight, painful knots in the muscles around the spine. They’re commonly used for conditions like fibromyalgia and myofascial pain syndrome, delivering the same combination of anesthetic and steroid into the muscle itself.
Nerve blocks take things a step further. If a diagnostic injection confirms which nerve is sending pain signals, a technique called radiofrequency ablation can damage that nerve with heat to block pain more permanently. Because the nerve is sensory and regenerates over time, the relief typically lasts several months before the procedure may need repeating.
Three Approaches for Epidural Injections
Epidural injections can reach the spine through different routes, and your doctor will choose one based on your anatomy and the location of your pain.
The interlaminar approach enters between two adjacent vertebral plates at the back of the spine, passing through several layers of ligament before reaching the epidural space. Because the medication spreads broadly in this approach, it works well for people with pain at multiple spinal levels or central canal narrowing.
The transforaminal approach threads the needle through the natural opening (foramen) where nerve roots exit the spine. This delivers medication closer to a specific nerve root, making it the go-to choice for one-sided leg pain caused by a disc herniation or narrowing around a single nerve.
The caudal approach enters through a small opening at the base of the sacrum, the triangular bone at the bottom of the spine. This route is often preferred for people who have had prior back surgery, since scar tissue or altered anatomy can make the other approaches more difficult.
What Happens During the Procedure
You’ll lie face down on a procedure table, usually with a pillow under your abdomen to flatten the curve of your lower back and give the doctor a better view. The skin over the injection site is cleaned and draped, and the area is numbed with a local anesthetic before the spinal needle is inserted.
The doctor uses fluoroscopy, a form of live X-ray, to watch the needle’s position in real time. Once the needle reaches the target, a small amount of contrast dye is injected to confirm the medication will flow to the right spot. Then the actual medication, typically a steroid combined with a long-acting anesthetic, is delivered. The whole process generally takes 15 to 30 minutes.
How Well Do They Work?
Spinal injections help a meaningful number of people, but they don’t work for everyone. In a study tracking 108 patients after epidural steroid injections, about 47% achieved at least a 50% reduction in pain by the three-week mark. Among those responders, roughly 73% noticed significant relief within the first day, and another 22% reached that threshold by day four.
The other side of that coin: about 53% of patients were non-responders who never reached sustained 50% relief. Interestingly, a third of non-responders did feel substantial relief on day one, but the effect faded within the first week. So early relief alone doesn’t guarantee lasting benefit, and it can take up to three weeks to know whether the injection truly worked for you.
When injections do work, the pain relief can last weeks to several months. The steroid component takes a few days to reach full effect, which is why doctors often say to give it time even if the initial numbing wears off quickly.
Risks and Safety
Spinal injections are considered low-risk procedures, but they’re not risk-free. Common, mild side effects include temporary soreness at the injection site, a brief increase in pain, and occasional flushing or a mild headache.
Serious complications are rare. A large study of over 1.3 million epidural steroid injections in Medicare patients found the rate of serious spinal adverse events was roughly 8 per million. Nearly all of those serious cases involved epidural hematomas (blood collections pressing on the spinal cord), and most required emergency surgery. The risk was notably higher for injections in the neck and upper back (about 29 per million) compared to the lower back (about 5 per million). Patients taking blood thinners or aspirin had a disproportionate presence among the serious cases.
Guidelines from CMS limit epidural steroid injections to a maximum of four sessions per spinal region in a rolling 12-month period. Continuing injections beyond 12 months requires documented evidence that each injection provides at least 50% sustained improvement in pain or function.
How to Prepare
If you take blood thinners or aspirin, your doctor will give you specific instructions about whether and when to stop them before the procedure. You may also be told not to eat or drink for a set period beforehand, particularly if sedation is planned. Arrange for someone to drive you home, since the anesthetic used during the injection can make it unsafe to drive yourself.
Recovery After the Injection
Most people go home the same day. You can eat normally afterward, and soreness at the injection site is typical. Applying ice wrapped in a thin cloth for 10 to 20 minutes at a time helps with tenderness. Avoid baths for the first 24 hours, though showers are generally fine.
Your doctor will let you know when to restart any medications that were paused before the procedure. Watch for signs that something isn’t right: new or worsening pain, numbness or weakness in your legs or buttocks, severe headache, loss of bowel or bladder control, or signs of infection like increasing redness, swelling, warmth, or fever. Any of these warrant a prompt call to your doctor or, in the case of trouble breathing or loss of consciousness, a call to 911.