A spinal injection is a procedure that delivers medication, typically a steroid and a local anesthetic, directly into or near the spine to reduce pain and inflammation. It’s one of the most common non-surgical treatments for back and neck pain, used both to diagnose where pain is coming from and to provide weeks or months of relief. Most spinal injections are outpatient procedures that take 15 to 30 minutes.
How Spinal Injections Work
The basic idea is straightforward: instead of taking oral pain medication that circulates through your entire body, a spinal injection puts anti-inflammatory medicine right at the source of the problem. The local anesthetic blocks the electrical signals that nerves use to transmit pain sensations to the brain, providing immediate but temporary relief. The steroid component works more slowly, reducing inflammation around compressed or irritated nerves over the following days. Together, these two medications can break the cycle of inflammation, nerve irritation, and pain that keeps chronic back or neck problems from improving on their own.
Common Types of Spinal Injections
Not all spinal injections go to the same place. The type you receive depends on where your pain originates and whether the goal is diagnosis, treatment, or both.
Epidural steroid injections are the most widely used. The medication goes into the epidural space, the area surrounding the spinal cord and nerve roots. These are primarily therapeutic, meaning the goal is lasting pain relief. They’re commonly used for herniated discs, spinal stenosis, and degenerative disc disease. A study of cervical epidural steroid injections found that about 41% of patients had excellent pain relief (90% or greater reduction) lasting six months, while another 29% had good results with more than 50% pain relief lasting at least six weeks. Patients with degenerative joint disease tended to respond significantly better than those with other diagnoses.
Facet joint injections and medial branch blocks target the small joints that connect each vertebra to the ones above and below it. Medial branch blocks numb the tiny nerves that supply these joints. These are primarily diagnostic tools: if the injection eliminates your pain, it confirms that a specific facet joint is the source. Once the pain source is identified, longer-lasting treatments like radiofrequency neurotomy (which uses heat to interrupt pain signals from that nerve) can follow.
Selective nerve root blocks inject medication around a single spinal nerve where it exits the spine. These help pinpoint which specific nerve is causing your symptoms, particularly useful when imaging shows problems at multiple levels but your doctor needs to know which one is actually responsible for your pain. Their diagnostic accuracy depends on precise needle placement and the volume of medication used.
Diagnostic vs. Therapeutic Injections
This distinction matters because it shapes what you should expect from the procedure. Medial branch blocks, selective nerve root blocks, and a procedure called diskography are purely diagnostic. Their purpose isn’t long-term relief. They’re tests, essentially: if numbing a specific structure eliminates your pain temporarily, your doctor has identified the source and can plan targeted treatment. On the other hand, epidural steroid injections and radiofrequency neurotomy are therapeutic, meaning their goal is sustained pain reduction. Some procedures serve both purposes simultaneously, providing useful diagnostic information while also delivering meaningful relief.
What Happens During the Procedure
You’ll lie face down on a table while the doctor uses imaging guidance, either real-time X-ray (fluoroscopy) or CT scanning, to see your spine and guide the needle precisely. The skin is numbed with a local anesthetic first, so you’ll feel pressure but generally not sharp pain.
The doctor advances a thin needle toward the target area, checking its position on the imaging screen at several points along the way. Once the needle reaches the right depth, a small amount of contrast dye is injected. This dye shows up on imaging and confirms the needle tip is in the correct space, not inside a blood vessel or the spinal fluid. If you have a contrast allergy, air or an alternative agent can be used instead. Once positioning is confirmed, the steroid and anesthetic mixture is injected, the needle is removed, and the procedure is done.
Most people go home the same day. You may feel numbness or mild weakness in the affected area for a few hours from the anesthetic. The steroid typically takes two to seven days to reach its full effect, so don’t judge the results on day one.
How Many Injections You Can Have
Spinal injections aren’t unlimited. Medicare guidelines cap epidural steroid injections at four sessions per spinal region in a 12-month period. The North American Spine Society recommends no more than four injections within any six-month window and no more than six in a full year, regardless of how many spinal levels are involved. These limits exist because repeated steroid exposure can weaken bone density and surrounding tissues over time. If you’re not getting meaningful relief after a few rounds, your doctor will typically recommend a different approach rather than continuing injections indefinitely.
Who Should Not Get a Spinal Injection
Some situations rule out the procedure entirely. Active infection at the injection site, sepsis, or bacteria in the bloodstream are absolute contraindications because the injection could spread infection to the spine. Fractures in the area and significant joint instability are also reasons to avoid steroid injections, since steroids can inhibit bone healing and weaken joint structures.
Other situations call for caution rather than outright avoidance. If you’re on blood thinners, your doctor will likely need to adjust your medication beforehand because of the bleeding risk. Severe osteoporosis near the injection site raises concern about further bone density loss from steroids. A true allergy to local anesthetics also needs to be discussed ahead of time, though allergies to one class of anesthetic don’t necessarily rule out all of them.
Risks and Complications
Most spinal injections are completed without serious problems, but the risks are real and worth understanding. Common side effects include temporary soreness at the injection site, mild headache, and occasionally a brief increase in pain before improvement begins.
More serious complications are uncommon but documented. Dural puncture, where the needle goes slightly too deep and punctures the membrane surrounding the spinal fluid, can cause a persistent headache that worsens when you sit or stand. Infection, including epidural abscess, is rare but serious. Bleeding that forms a hematoma in the epidural space can compress nerves. One study of patients admitted to a spinal cord injury center found that 7 out of 1,343 patients (about 0.5%) had cervical injuries attributed to spinal injections, resulting from causes including cord injection, epidural abscesses, hematomas, and cord contusion.
Cervical (neck) injections carry higher risk than lumbar (lower back) injections because of the proximity to the vertebral arteries and the spinal cord itself. Serious neurological events, including stroke and paralysis, have been reported with cervical injections, particularly those using the transforaminal approach where the needle enters from the side. This is one reason imaging guidance during the procedure is considered essential rather than optional.
What Results to Expect
Spinal injections work best for specific conditions. People with disc herniations pressing on a nerve root and those with degenerative joint disease tend to have the strongest outcomes. Visible nerve compression on MRI has been linked to significant improvement at three months after injection. For patients whose imaging shows annular tears (small disruptions in the outer disc wall), relief tends to be more noticeable in the first two weeks.
Relief duration varies widely. Some people get months of significant pain reduction from a single injection, while others notice only a few weeks of improvement. The injections don’t fix the underlying structural problem. They reduce inflammation to give your body a window to heal, or they provide enough relief to make physical therapy and exercise possible. When they work well, they can help you avoid or delay surgery. When they don’t, the information gained from the injection still helps guide the next step in treatment.