A cortisone flare is a temporary spike in pain and swelling that happens after a steroid injection, and treating it at home is straightforward: ice the area, rest the joint, and take an over-the-counter pain reliever. About 33% of people who get steroid injections experience this reaction, so if you’re dealing with one, it’s common and almost always resolves on its own within a few days.
What a Cortisone Flare Actually Is
When a steroid is injected into or near a joint, the medication often contains tiny crystals that can irritate the surrounding tissue. Your body reacts to these crystals the same way it would react to any foreign irritant: with inflammation. The result is a temporary increase in pain, swelling, and sometimes warmth at the injection site that can feel worse than the original problem you were treating.
This reaction typically begins within the first 24 hours after the injection and peaks around 24 to 48 hours. Most flares settle down within two to three days. The important thing to understand is that this is a short-lived inflammatory response, not a sign that the injection failed. Once the crystals dissolve and the steroid starts working, you should begin to feel the relief you were expecting from the shot in the first place.
Ice Is Your Best Immediate Tool
Icing the injection site is the single most effective home treatment for a cortisone flare. Apply an ice pack or a bag of frozen vegetables wrapped in a thin towel directly over the area for 10 to 20 minutes at a time. Don’t go beyond 20 minutes in a single session, as prolonged cold exposure can damage skin and tissue.
Space your icing sessions at least one to two hours apart, and continue this pattern for two to four days if it’s helping. Avoid heating pads, hot tubs, whirlpools, and hot baths for at least two days after the injection. Heat increases blood flow and can worsen the swelling and pain. This is the opposite of what you want during an active flare.
Rest and Protect the Joint
For the first day or two after the injection, reduce the demands you place on the affected area. If you had a knee injection, stay off your feet as much as possible. If the shot was in your shoulder, skip heavy lifting. The goal is to give the tissue time to calm down without adding mechanical stress on top of the crystal-induced irritation.
Elevating the area when you can also helps. If the injection was in a lower extremity, propping your leg up on a pillow reduces fluid pooling at the site and can ease that tight, swollen feeling. You don’t need to be completely immobile, but this isn’t the time to test the joint with exercise or strenuous activity.
Over-the-Counter Pain Relief
Anti-inflammatory pain relievers like ibuprofen or naproxen can help manage both the pain and the inflammation driving the flare. These work by dialing down your body’s inflammatory response to the crystals, which addresses the root of the problem rather than just masking the discomfort. Acetaminophen is another option if you can’t take anti-inflammatories due to stomach sensitivity or other reasons, though it won’t reduce the swelling itself.
Follow the dosing instructions on the package and don’t combine multiple pain relievers without checking that they’re safe to take together. If you’re already on prescription medications, verify with your pharmacist that there are no interactions.
What to Expect Day by Day
The worst of a cortisone flare usually hits within the first 24 to 48 hours. During this window, the joint may feel hot, stiff, and noticeably more painful than it was before the injection. Some people describe it as feeling like the joint is “angry.” This is normal.
By day two or three, you should notice the flare starting to fade. The swelling decreases, the sharp pain shifts to a dull ache, and range of motion begins to return. By day four or five, most people are through the flare entirely and starting to feel the actual benefit of the steroid injection. If you’re still getting worse after 72 hours rather than improving, that’s a signal to contact your provider.
When Pain Could Signal Something Else
A cortisone flare and a joint infection can look similar in the early stages, which is why it’s important to know the differences. A flare causes localized pain and swelling that begins to improve within two to three days. A joint infection, while rare, tends to get progressively worse rather than better.
Key warning signs that suggest infection rather than a simple flare include fever, intense warmth across the entire joint (not just the injection spot), severe pain that makes the joint almost impossible to move, and redness that spreads outward from the injection site. Infections after joint injections typically present around 72 hours after the procedure. If you develop a fever or notice your symptoms escalating rather than plateauing and improving, contact your provider promptly. Joint infections require fast treatment to prevent damage.
The distinguishing pattern is direction of change: a flare peaks and then improves, while an infection steadily worsens. If you’re unsure which you’re experiencing, erring on the side of getting checked is reasonable.
Reducing the Chance of a Future Flare
If you’ve had a cortisone flare once, you may be more likely to experience one again with future injections, though this isn’t guaranteed. Let your provider know about your previous reaction before your next injection. They may adjust the formulation, change the type of steroid used, or mix in a local anesthetic to reduce the post-injection pain response.
Planning your injection timing can also help. If you know a flare is possible, schedule the shot before a rest day or weekend rather than right before you need to be active. Having ice packs ready and an anti-inflammatory on hand means you can start managing symptoms immediately rather than scrambling while already in pain.