Can Epidural Steroid Injections Make Pain Worse?

Epidural steroid injections can make pain worse, and they do so more often than many patients expect. Roughly one in five people experience a temporary pain flare in the days following the procedure, and a smaller fraction report increased pain that lingers beyond that window. Beyond these common flares, rarer complications ranging from infection to direct nerve damage can create entirely new pain problems. The story is more layered than a simple yes-or-no, though, because the type of injection, the location in the spine, and the patient’s anatomy all shift the odds.

The Post-Injection Pain Flare

The most frequent way an epidural steroid injection (ESI) makes pain worse is the post-injection flare: a spike in pain that usually begins within hours and resolves within a few days. In a prospective study tracking musculoskeletal corticosteroid injections, about 21% of patients reported a flare of pain afterward. Younger patients were more likely to experience one, with the odds of a flare dropping roughly 5.5% for each additional year of age. Factors you might expect to matter, like injection site, body mass index, baseline pain level, and the specific steroid used, had no significant effect on whether a flare occurred.¹

The flare is thought to stem from the needle itself irritating local tissue, from the volume of fluid suddenly introduced into a tight space, or from a brief crystal-induced inflammatory reaction when steroid particles settle against nerve tissue. It can feel alarming, especially if you were told the injection would bring relief. But in most cases, the flare burns out within 48 to 72 hours, and any therapeutic benefit from the steroid kicks in over the following week or two. Ice, over-the-counter anti-inflammatories, and rest are the usual recommendations for riding it out.

A multi-institutional study looking specifically at ESIs found that about 2% of patients reported increased pain at follow-up, regardless of whether the injection was transforaminal or interlaminar. That same study also found that about 2.6% of patients experienced systemic steroid effects like sleeplessness, flushing, or non-positional headaches, all of which can compound the sense that the injection made things worse even when the spine itself is not actually deteriorating.²

How the Injection Route Changes the Risk Profile

Not all epidural steroid injections are performed the same way. The three main approaches each come with a different balance of precision and risk. A transforaminal injection threads the needle through the neural foramen to deliver medication close to a specific nerve root. An interlaminar injection enters between the vertebral laminae, spreading medication more broadly. A caudal injection enters from the sacral hiatus at the base of the spine, which is the easiest trajectory but delivers the least targeted dose.³

The transforaminal approach gets medication closest to the inflamed nerve root, which makes it effective for focal radicular pain. But it also carries a higher risk of nerve injury and vascular compromise because the needle passes near critical structures. The interlaminar approach is technically simpler but is less precise in reaching the right target, and it carries a slightly higher rate of accidental dural puncture. In the multi-institutional study mentioned earlier, vasovagal reactions were more common with the transforaminal approach (1.3% vs. 0.5%), while accidental dural punctures happened more often with the interlaminar approach (0.2% vs. 0.04%).²

Where the risk calculus really shifts is in the cervical spine. Over the past two decades, reports have accumulated of rare but devastating neurological injuries during cervical and thoracic transforaminal injections, particularly when particulate corticosteroid preparations were used. If a particulate steroid enters a blood vessel feeding the spinal cord, it can cause an embolism that leads to stroke-like damage. This led the FDA to introduce warning labels for injectable corticosteroids regarding the risk of serious neurological events, and many guidelines now advise using only non-particulate steroids (like dexamethasone) for cervical transforaminal injections.⁴

Direct Needle Injury to the Spinal Cord or Nerve Roots

The most feared complication of any epidural injection is direct mechanical damage to neural tissue. It is rare, but when it happens, it can be catastrophic. A case report documented a patient who underwent a cervical transforaminal injection under fluoroscopic guidance at C6-7, felt a shooting pain during needle insertion, and developed quadriparesis shortly afterward. Imaging confirmed that the needle had penetrated the spinal cord and contrast material had been injected into the cord itself.⁵

A case series examining multiple instances of direct spinal cord injury during cervical epidural and nerve root blocks found a consistent pattern: patients reported an instantaneous, excruciating “electric shock-like” sensation during needle insertion, followed immediately by severe motor weakness and abnormal sensations. MRI scans showed central cord lesions consistent with direct mechanical puncture rather than vascular compromise.⁶

One reassuring finding: the sharp, radiating pain many patients feel during needle insertion does not reliably predict lasting nerve damage. A retrospective review found that the radiating pain experienced during epidural needle placement was not significantly associated with persistent paresthesia afterward. In other words, a brief zap during the procedure does not mean the nerve has been permanently harmed.⁷

Infection and Bleeding

Any time a needle enters the body near the spine, there is a small risk of introducing bacteria into the epidural space. An epidural abscess can form, creating pressure and inflammation that cause severe new pain, fever, and potentially permanent neurological damage if not caught quickly. One case involved a 24-year-old man who developed fever, low back pain, and bilateral leg pain a week after a CT-guided nerve root block. Blood cultures grew Staphylococcus aureus, and MRI revealed a posterior epidural collection stretching from T12 to L5.⁸ Another case documented epidural abscess with meningitis in a 70-year-old man after two epidural steroid injections for acute radicular back pain; cerebrospinal fluid cultures also grew Staphylococcus aureus.⁹

Spinal epidural hematoma is another serious complication. Blood collecting in the epidural space can compress the spinal cord or cauda equina, producing sudden leg weakness and pain. A case report described a 76-year-old woman with mild lumbar stenosis who developed bilateral leg paralysis after a lumbar ESI at T12-L1. She had been on low-dose aspirin, which she stopped two weeks before the procedure, and was not on anticoagulation therapy. MRI showed a fluid collection consistent with hematoma.¹⁰ While both abscess and hematoma are rare, they are emergencies that require immediate medical attention. Patients on blood thinners or with compromised immune systems face elevated risk.

Pressure Buildup Inside the Epidural Space

The epidural space is a confined compartment, and injecting fluid into it raises the pressure inside. Most of the time this is harmless and temporary, but when the fluid becomes trapped in a pocket rather than dispersing evenly, the sustained pressure can squeeze nearby blood vessels and compromise blood flow to nerve roots or the lower spinal cord. Documented consequences of this kind of pressure buildup include transient urinary retention, temporary radiculopathy, and even brief episodes of paralysis.¹¹

Patients with severe spinal stenosis are more vulnerable here because the space available for the epidural contents is already limited. Injecting additional volume into a canal that is already tight increases the chance of focal pressure spikes. This is one reason clinicians typically use the smallest effective injection volume and monitor patients closely for neurological changes immediately after the procedure.

Arachnoiditis From Epidural Steroids

Adhesive arachnoiditis is a chronic condition in which the membranes surrounding the spinal cord and nerve roots become inflamed and scarred, clumping nerve roots together. It can cause burning pain, numbness, and bowel or bladder dysfunction, and it is largely untreatable once established. There are documented cases of arachnoiditis developing after lumbar epidural steroid injections. A report of two patients who received transforaminal and interlaminar injections found clear MRI evidence of arachnoiditis afterward, though interestingly, the radiological changes did not correspond to any worsening of the patients’ clinical symptoms.¹²

The medical literature describes arachnoiditis after ESI as rare, and its exact cause in these cases remains uncertain. It could stem from the steroid itself irritating the arachnoid membrane, from preservatives in the injectable formulation, or from the needle inadvertently introducing blood or other material into the subarachnoid space. The clinical spectrum is wide: some patients are diagnosed incidentally on imaging with no symptoms at all, while others develop severe and disabling pain.

What Preservatives and Additives Can Do

The steroid vial itself contains more than just corticosteroid. Commercially available injectable corticosteroid formulations include additives such as benzyl alcohol, polyethylene glycol, polysorbate 80, and sodium sulfite, among others. Animal studies and some clinical observations suggest these additives have potential neurotoxic effects when they come into direct contact with neural tissue.¹³ This is one of the reasons many pain specialists prefer preservative-free formulations when available, though access varies by institution and region.

In rare instances, the contrast dye used during fluoroscopy-guided injections can also trigger reactions. One case involved a woman who developed a hypersensitivity reaction to iohexol, the contrast agent used during her fluoroscopically guided interlaminar ESI.¹⁴ If you have a known allergy to contrast dye, it is critical to tell your physician before any image-guided spinal injection.

Bone Loss and Fracture Risk With Repeated Injections

Corticosteroids, even when injected locally, enter the bloodstream and can have systemic effects. One of the most concerning long-term consequences of repeated ESIs is bone mineral loss. A large retrospective study of older individuals with radiculopathy found that those who received ESIs had a roughly 39% higher risk of fracture at typical osteoporotic sites compared to those who did not. The risk was even greater for vertebral fractures specifically, with an increase of about 54%. Patients who received three or more injections in a single year faced the highest risk, particularly within the first six months after the injections.¹⁵

A separate retrospective cohort study examining patients with lumbar degenerative disease reached a similar conclusion: ESIs were associated with an increased risk of osteoporotic vertebral compression fractures. The concern is not just that steroids circulate systemically and weaken distant bone, but that local deposition of corticosteroid in the lumbar spine may directly compromise bone density in the very vertebrae surrounding the injection site.¹⁶ This matters practically because vertebral fractures cause exactly the kind of severe back pain that ESIs are meant to treat, setting up a perverse cycle where the treatment contributes to a future pain-generating event.

What Repeated Corticosteroid Exposure Does to Soft Tissue

The effects of repeated corticosteroid injections extend beyond bone. A pilot study of patients with chronic rotator cuff tears who received frequent local corticosteroid injections found that these injections appeared to accelerate fatty infiltration of the muscle and promote muscle atrophy. At the molecular level, the injections upregulated genes associated with fat accumulation and muscle wasting while suppressing genes related to new muscle formation.¹⁷

This study examined shoulder injections rather than epidural ones, so you cannot directly extrapolate these tissue-level findings to the spine. But the underlying biology is the same: corticosteroids promote fat deposition and discourage muscle repair regardless of where they end up. For spinal patients, the clinical takeaway is that more injections is not simply more treatment. There are diminishing returns and accumulating tissue costs, which is why most guidelines recommend limiting the number of ESIs a patient receives in a given year.

Who Is More Likely to Benefit and Who Isn’t

One of the persistent frustrations with ESIs is how variable the outcomes are from person to person. A prospective study from Thailand attempted to identify predictive factors for a favorable response to lumbar transforaminal ESIs. Patients with mild central canal stenosis had nearly five times the odds of a favorable outcome compared to those with severe stenosis.¹⁸ In other words, if the canal is already very tight, the injection is less likely to help and the risks described earlier (pressure buildup, inadequate delivery) become more relevant.

Gender may also play a role in how pain responds to ESI, though the evidence is still early. A study tracking pain, anxiety, and disability after ESIs for low back pain found that females reported significantly lower pain scores at both three and six weeks post-injection compared to males. Disability scores were also lower in females. Interestingly, anxiety and depression scores did not differ between the groups at any time point, suggesting the difference was not explained by psychological factors alone.¹⁹

Patients with acute, single-level disc herniations causing clear radicular symptoms tend to respond better than patients with diffuse, multi-level degenerative disease. The injection works best when there is a discrete inflammatory target. When pain is generated by widespread structural degeneration, a single bolus of steroid at one level is fighting a losing battle, and the patient may end up feeling that the injection accomplished nothing, or that the brief flare left them worse than they started.

When Worsening Pain Means Something Else Entirely

Sometimes pain increases after an ESI not because of anything the injection did, but because the underlying condition continued to progress during the period when the patient was waiting for the shot to work or when the previous injection’s relief was wearing off. Spinal stenosis narrows over months and years. Disc herniations can enlarge. Facet joints degenerate. A patient who felt decent for eight weeks after an injection and then experiences worsening pain is not necessarily experiencing a side effect of the injection. They may simply be experiencing the natural course of their disease, now unmasked because the anti-inflammatory effect has faded.

This distinction matters because it changes what you do next. If an ESI made your pain genuinely worse through a complication like infection, hematoma, or nerve injury, you need urgent evaluation and possibly emergency treatment. If your pain returned or gradually worsened because the steroid wore off and your spine continued to deteriorate, the conversation shifts to whether another injection, physical therapy, or surgery is the appropriate next step. Keeping a pain diary with dates and severity levels can help your physician sort out which scenario is more likely. A sudden spike in pain immediately after the injection suggests a procedure-related cause; a slow return to baseline over weeks suggests the underlying condition is driving the bus.