If your doctor has suggested a cortisone shot for a painful joint or tendon, you probably have two questions: will it actually help, and is it safe to keep getting them? Both have real answers, but the honest version is more nuanced than either "it is a miracle" or "it wears out your joint." Here is what a cortisone injection does, how long it tends to last, and where the real limits are.
What is actually in the shot
Despite the name, a cortisone shot is not a painkiller in the usual sense. It is a corticosteroid, a potent anti-inflammatory medication, usually combined with a local anesthetic that numbs the area for the first few hours. The steroid does not repair anything. What it does is calm the inflammation that is driving your pain, which can break a cycle of swelling and irritation long enough for the area to settle down.
That distinction matters. Cortisone treats the inflammation, not the underlying problem. If the cause is mechanical, such as a bone spur or worn cartilage, the shot can quiet the symptoms while the structural issue remains.
What it treats well, and what it treats less well
Cortisone injections are used across a wide range of orthopaedic problems, but they do not work equally well for all of them. In general, conditions dominated by active inflammation respond best.
| Condition | Typical response to cortisone |
|---|---|
| Shoulder impingement / bursitis | Often good, especially early |
| Trigger finger | Frequently resolves with 1-2 injections |
| Carpal tunnel syndrome | Good short-term relief; often temporary |
| Knee or hip osteoarthritis | Variable; relief often measured in weeks to a few months |
| Tennis elbow | Short-term relief, but may not beat waiting it out long-term |
| Plantar fasciitis | Can help, with a small risk to the fascia |
The pattern here is that cortisone is often excellent for a flare and less impressive as a long-term fix. For something like trigger finger it can be close to curative. For arthritis it is better understood as a way to buy comfortable months, not a permanent solution.
How long relief lasts
This is the question patients ask most, and the honest answer is that it varies a lot. Some people get a few weeks of relief, others get several months, and a fortunate few find that a single well-timed injection settles the problem for good. For arthritis, three months is a reasonable average expectation, though it can be shorter or longer.
The anesthetic mixed in gives many people near-immediate relief for a few hours. That often wears off before the steroid takes effect, so it is common to feel good, then sore again, then gradually better over three to seven days. If your pain briefly worsens in the first day or two, that is usually a normal steroid flare, not a sign that something went wrong.
How many can you safely get
There is no single hard rule, but there is a widely used rule of thumb: no more than three to four injections into the same joint per year, spaced at least six weeks to three months apart. The caution behind that number is not arbitrary.
Repeated corticosteroid exposure can weaken nearby tissue over time. A frequently cited concern is cartilage. A 2017 randomized trial in patients with knee osteoarthritis found that injections every three months for two years provided no better pain relief than saline and were associated with slightly greater cartilage loss on imaging. That does not mean one or two shots harm your knee, but it is a good reason not to treat cortisone as something you top up indefinitely.
Steroids can also weaken tendons, which is why doctors are cautious about injecting directly into or around load-bearing tendons like the Achilles or patellar tendon, where rupture is a known if uncommon risk.
Side effects to expect
Most cortisone injections are uneventful, but a few effects are common enough to expect.
A post-injection flare of pain in the first 24 to 48 hours settles on its own. A temporary rise in blood sugar is normal in people with diabetes and can last several days, so it is sensible to monitor more closely than usual. Some people notice facial flushing for a day or two. Less commonly, the steroid can cause a small dimple or lightening of the skin at the injection site, from thinning of the fat and pigment just under the surface, which may or may not fully recover.
The most serious risk, infection in the joint, is rare because injections are done under sterile conditions. Still, worsening pain, redness, swelling, and fever in the days after a shot is a reason to call your doctor promptly rather than wait.
What to expect on the day
The injection itself takes only a few minutes. Your doctor cleans the skin, sometimes uses ultrasound to guide the needle to the right spot, and injects the mixture. You may feel pressure or a brief ache as the fluid goes in. Afterward it is sensible to rest the area for a day or two rather than immediately test it with heavy activity, even if the anesthetic makes it feel great at first.
The bottom line
A cortisone shot is a useful tool for calming inflammation and getting you through a painful stretch, and for some conditions it does much more than that. It is not a repair, and it is not something to lean on every few weeks. If you find yourself needing frequent injections just to function, that is a signal to revisit the underlying diagnosis with your orthopaedic specialist and talk about longer-term options, whether that is physical therapy, a brace, or in some cases surgery.
