After an SI joint injection, the first priority is straightforward: take it easy for the rest of the day, arrange for someone else to drive you home, and start paying close attention to your pain levels over the next several hours and days. The injection itself is quick, but what you do afterward affects both your comfort and how useful the results are for guiding your treatment. Most clinics send patients home with a brief instruction sheet, but the real picture of post-injection life is more nuanced than “rest and ice.”
Getting Home and the First Few Hours
Most pain clinics require you to have a driver. A survey of interventional pain practices found that the majority of providers required patients to have someone drive them home after joint injections and nerve blocks, with trigger point injections being the only common exception.1Dove Press / Journal of Pain Research. A review and survey of policies utilized for interventional pain procedures: a need for consensus This is partly because local anesthetic is typically injected alongside the steroid, and the temporary numbness can affect how your leg and pelvis feel for the first few hours. You may notice that your usual SI joint pain has vanished almost immediately, which can feel dramatic. That relief comes from the anesthetic, not the steroid, and it usually wears off within a few hours.
During those first hours, keep activity light. Walking around your home is fine, but avoid heavy lifting, vigorous exercise, or prolonged sitting in one position. Applying ice to the injection site for 15 to 20 minutes at a time can help with any soreness from the needle itself. Some providers recommend avoiding anti-inflammatory medications for the first day or two to let the steroid settle in without interference, though this varies by clinic. If your doctor gave you specific instructions, follow those over any general advice.
Expect a Possible Pain Flare
One thing that catches many people off guard is a temporary increase in pain after the injection. In a prospective study of 140 patients who received musculoskeletal corticosteroid injections, about one in five reported a flare of pain afterward.2PubMed Central. Prospective Evaluation of Pain Flares and Time Until Pain Relief Following Musculoskeletal Corticosteroid Injections The flare typically happens once the local anesthetic wears off but before the steroid kicks in, creating a window where the joint feels worse than it did before you walked into the clinic. This is not a sign that something went wrong.
Younger patients were more likely to experience a post-injection flare in that same study, while factors like body weight, gender, and the type of corticosteroid used made no difference.2PubMed Central. Prospective Evaluation of Pain Flares and Time Until Pain Relief Following Musculoskeletal Corticosteroid Injections If you do get a flare, ice and over-the-counter pain relief usually manage it. Most flares resolve within a day or two, and the steroid’s anti-inflammatory effect generally begins building over the first 48 to 72 hours, with many patients noticing meaningful relief within the first week.
Bathing, Swimming, and Showering
You have probably been told to keep the injection site dry for 24 hours, or to avoid pools and hot tubs. This is one of the most common pieces of post-procedure advice, and it turns out there is not much behind it. A review published in Pain Medicine examined the evidence and concluded there is no clear link between bathing, swimming, or using hot tubs after a needle-based interventional spine procedure and an increased risk of infection.3Pain Medicine. Bathing and Swimming After Interventional Spine Procedures The review categorized the 24-hour bathing restriction as a medical myth rather than an evidence-based guideline.
That said, common sense still applies. The injection site is essentially a tiny needle puncture. Keeping it clean is reasonable, and if you have any bandage on it, you can remove it after a few hours. If your doctor specifically told you to stay out of the water, there may be a patient-specific reason for it, but for the average person, a normal shower the evening of the procedure is unlikely to pose any risk.
Why Tracking Your Pain Matters More Than You Think
An SI joint injection is often as much a diagnostic test as it is a treatment. Your doctor wants to know whether numbing and reducing inflammation in the SI joint actually changes your pain. If it does, that confirms the SI joint is genuinely the source of your symptoms, which shapes every treatment decision that follows. If the injection does not help much, your pain may be coming from somewhere else entirely, like a disc, a facet joint, or a hip problem.
This is why keeping a pain diary in the hours and days after your injection is so valuable. Researchers have recommended tracking pain scores with a log to get an accurate picture of the patient’s response.4PubMed Central. Successful Diagnosis of Sacroiliac Joint Dysfunction Write down your pain level on a simple 0-to-10 scale every few hours on injection day, then once or twice daily for the next week or two. Note what you were doing at the time, whether you were sitting, standing, or walking. Pay special attention to the period while the local anesthetic is still active, usually the first two to six hours, because that window is the clearest diagnostic signal.
The threshold for what counts as a “positive” diagnostic block has gotten stricter over time. Historically, a 50 percent reduction in pain was considered the diagnostic cutoff for confirming SI joint dysfunction. More recently, experts have moved toward requiring 75 percent relief, and some recommend dual diagnostic blocks, meaning two separate injections on different occasions, before pursuing more aggressive treatment.4PubMed Central. Successful Diagnosis of Sacroiliac Joint Dysfunction Bringing your pain log to your follow-up appointment gives your doctor the data to make those calls with confidence rather than relying on your fuzzy memory of how the week went.
Blood Sugar Concerns for People with Diabetes
If you have diabetes, steroid injections deserve some extra attention. Corticosteroids are well known to raise blood sugar, and SI joint injections are no exception. A study of patients with diabetes who received musculoskeletal steroid injections found that blood glucose rose significantly the day after the injection compared to baseline.5PubMed Central. Changes in Blood Glucose Level After Steroid Injection for Musculoskeletal Pain in Patients With Diabetes By the second day, blood glucose had generally returned to baseline levels, so the spike tends to be short-lived.
The degree of that spike was not uniform. Patients with poorer blood sugar control before the injection, specifically those with higher HbA1c levels, experienced a greater rise. Those on insulin also saw a larger glucose increase compared to patients managing diabetes without insulin.5PubMed Central. Changes in Blood Glucose Level After Steroid Injection for Musculoskeletal Pain in Patients With Diabetes The practical takeaway is to monitor your blood sugar more frequently for the first 48 hours after the injection and have a plan with your doctor for adjusting your medication if needed. If your diabetes is well controlled and you manage it with oral medications alone, the bump is likely to be modest. If you are on insulin with an HbA1c above 7 percent, talk to your endocrinologist or primary care doctor before the injection so you have a glucose management strategy in place.
Blood Thinners and Other Medications
One of the most anxiety-provoking questions around any injection procedure is whether to stop blood-thinning medications beforehand. The answer for SI joint injections is more reassuring than many patients expect. A large review of nearly 7,000 interventional pain procedures found that no complications attributable to anticoagulants occurred among the 4,766 procedures where blood thinners were continued. SI joint blocks were specifically identified as appearing safe in patients who stayed on their anticoagulants.6Pain Medicine. The Risks of Continuing or Discontinuing Anticoagulants for Patients Undergoing Common Interventional Pain Procedures
On the other side of the equation, among the 2,296 procedures where anticoagulants were stopped per guidelines, nine patients suffered serious complications, including two deaths, from blood clots that formed during the period off their medication.6Pain Medicine. The Risks of Continuing or Discontinuing Anticoagulants for Patients Undergoing Common Interventional Pain Procedures That does not mean stopping blood thinners is always wrong, but it highlights that the risk of discontinuing them is real and needs to be weighed against the risk of bleeding at the injection site. For a relatively superficial procedure like an SI joint block, many pain physicians now lean toward continuing anticoagulants. Discuss this directly with both your pain specialist and the doctor who prescribed your blood thinner.
Returning to Exercise and Physical Therapy
The steroid injection is not a standalone fix. It reduces inflammation to create a window where you can do the rehab work that addresses the underlying problem. Most providers recommend starting or resuming physical therapy within a week or two of the injection, once the steroid has had time to take effect and your pain has settled.
Physical therapy for SI joint dysfunction typically focuses on stabilizing the pelvis and strengthening the muscles around it, particularly the glutes, deep core muscles, and hip rotators. The joint itself has very little range of motion, so the goal is not to increase flexibility but to stop the joint from being loaded unevenly. Activity modification, physical therapy, and use of an SI belt are considered part of the initial treatment phase for sacroiliac joint pain.7Journal of the American Academy of Orthopaedic Surgeons. Management of Sacroiliac Joint Pain
An SI belt is a simple, non-elastic strap that wraps around the pelvis below your hip bones. It compresses the SI joint and can reduce the shearing forces that aggravate it during activity. Some people wear one during exercise or long periods of standing and find it noticeably helpful, while others do not feel much difference. It is inexpensive enough to be worth trying, and it carries no real downside.
As for returning to more vigorous exercise, let pain be your guide. If the injection provided good relief, you can gradually increase activity over the first two weeks. Running, heavy squatting, and activities involving twisting or single-leg loading tend to stress the SI joint the most, so bring those back last. If the injection did not help much, pushing through with intense exercise is unlikely to accomplish anything useful and may make you more sore.
What Happens If the Injection Works
If the injection gives you substantial relief, that is both good news and useful information. The good news is obvious: you feel better. The useful information is that the SI joint has been confirmed as a major pain source, which validates the diagnosis and opens the door to longer-term treatment options if the relief eventually fades.
Steroid injections for the SI joint typically provide weeks to a few months of relief, though this varies widely. Some people get six months or more, others notice the pain creeping back within a few weeks. Repeat injections are common, but most providers limit them to two or three per year to avoid the cumulative side effects of repeated corticosteroids, including cartilage thinning and the blood sugar issues described above.
If the injection works well but the pain keeps returning, radiofrequency neurotomy is often the next step. This procedure uses heat to disable the small nerves that carry pain signals from the SI joint. One factor worth knowing: younger patients tend to respond better to radiofrequency treatment of the SI joint, at least in terms of pain reduction and functional improvement.8PubMed Central. The effectiveness and predictive factors of Sacroiliac Joint Radiofrequency Neurotomy success – A retrospective cohort study Your response to the diagnostic injection is the single most important predictor of whether radiofrequency ablation or other advanced treatments will work, which is another reason that pain log matters so much.
What Happens If the Injection Does Not Help
A negative result, meaning the injection provided little or no relief, is still a useful result. It tells you and your doctor that the SI joint may not be the main pain generator, even if imaging or physical exam findings pointed toward it. SI joint dysfunction is notoriously difficult to diagnose because the symptoms overlap with lumbar disc problems, hip pathology, and piriformis issues. An injection that does not change your pain helps narrow the search.
There is one nuance here worth mentioning. A single negative injection does not definitively rule out the SI joint, especially if the injection was not performed under imaging guidance. Even with fluoroscopy or ultrasound, the medication does not always reach the right spot in the right concentration. That is part of why some guidelines recommend dual diagnostic blocks before concluding that the joint is or is not the problem.4PubMed Central. Successful Diagnosis of Sacroiliac Joint Dysfunction If your clinical picture strongly suggests the SI joint, your doctor may recommend a second injection before abandoning the diagnosis entirely.
Age also plays a role in how likely you are to respond. A retrospective study found that increasing age was associated with a lower likelihood of a positive outcome from SI joint injections, with the probability of a good response decreasing by about 9 percent for each additional year of age.9PubMed Central. Age predicts therapeutic outcome of imaging-guided sacroiliac joint injections, whereas osteoarthritis grade does not: A retrospective single-center study Interestingly, the severity of osteoarthritis visible on imaging did not predict the outcome. The joint can look terrible on a scan and respond beautifully, or look relatively normal and not respond at all. This disconnect between imaging and symptoms is one of the things that makes SI joint problems so frustrating for patients and clinicians alike.
When Surgery Enters the Conversation
If injections and radiofrequency ablation have confirmed that the SI joint is the pain source but have not provided lasting relief, some patients consider minimally invasive SI joint fusion. This is a procedure where a small implant is placed across the joint to stabilize it permanently. The evidence here is genuine but muddier than the marketing materials suggest.
A meta-analysis of randomized controlled trials and prospective cohort studies concluded that minimally invasive SI joint fusion improves pain and disability with low reoperation rates, but emphasized that outcomes depend heavily on rigorous patient selection and accurate identification of the SI joint as the primary pain generator through diagnostic injection.10Spine. Minimally Invasive SI Joint Fusion Improves Pain and Disability With Low Reoperation Rates: A Meta-Analysis of Randomized Control Trials and Prospective Cohort Studies In other words, fusion works best when the diagnosis is rock-solid.
A sham-controlled trial, which is the gold standard for surgical evidence because it accounts for the placebo effect of surgery itself, told a less clear-cut story. At six months, patients who received the actual fusion experienced about one point more pain reduction on a 10-point scale compared to patients who received a sham operation, and that difference was not statistically significant.11The Lancet. The effect of minimally invasive sacroiliac joint fusion compared with sham operation Half of the surgical group improved by at least two points, but so did 42 percent of the sham group.11The Lancet. The effect of minimally invasive sacroiliac joint fusion compared with sham operation That is a substantial placebo response, and it means that some of the benefit patients attribute to the surgery may come from the recovery process, the attention, or the simple belief that something was fixed. SI joint fusion remains a reasonable option for the right patient, but these results suggest that the bar for “the right patient” should be high. Your injection response, confirmed by a pain log and ideally by dual blocks, is the foundation of that decision.
Other Side Effects to Watch For
Beyond the pain flare and blood sugar effects already covered, corticosteroid SI joint injections carry a few other side effects worth knowing about. Facial flushing is common, particularly in women, and can last a day or two. Some people notice a temporary increase in appetite or mild insomnia for a few nights after the injection. These are systemic effects of the steroid and are not specific to the injection site.
Infection at the injection site is possible but rare, especially when the procedure is done under sterile conditions with imaging guidance. Watch for increasing redness, warmth, swelling, or fever in the days following the injection. A small bruise at the needle site is normal and does not require medical attention. Allergic reactions to the steroid or the contrast dye used during fluoroscopy are uncommon but can happen. If you have ever had a reaction to contrast dye or corticosteroids, tell your doctor before the procedure.
Weight gain from a single injection is unlikely, but patients who receive multiple injections over time sometimes notice gradual weight changes. If you are receiving SI joint injections more than two or three times a year, it is worth discussing cumulative steroid exposure with your provider. At that point, the conversation usually shifts toward whether a longer-lasting intervention like radiofrequency ablation makes more sense than continuing to manage symptoms with repeated injections.