A corticosteroid injection reduces inflammation in and around a joint, and NICE describes the relief as short-term, in the range of two to ten weeks. It is a window rather than a cure, and the rehabilitation done inside that window is what determines whether the joint is better in six months. Repeated injections into a knee with osteoarthritis every three months for two years produced greater cartilage volume loss than saline in a randomised trial, with no benefit for pain.
Injections around the spine work differently and are covered separately in PhysioHub’s guide to nerve root block injections and the rehab that follows.
In the order they matter, from the decision to have one through to the decision not to have another.
| Point | Timeframe | What it changes |
|---|---|---|
| 1. What it does | 2 to 10 weeks of relief | Sets realistic expectations before you agree to it |
| 2. The post-injection flare | First 24 to 48 hours | Stops you thinking it has gone wrong |
| 3. The rehabilitation window | Weeks 1 to 10 | This is what decides the six-month result |
| 4. Repeat injections | Over months and years | Changes whether you have a third and fourth |
| 5. When it is wrong | Before you start | Some joints do better without one |
The single most useful reframing is that an injection does not treat the problem. It removes pain for a period, and pain is usually what has been preventing the treatment. Used that way it is genuinely valuable; used as the treatment itself it buys a couple of months and returns you to where you started.
This is a documentary review of published guidance and trial evidence rather than advice about your particular joint. Five points were selected on how much each affects the decision to have an injection or the outcome afterwards.
The sources read were NICE guideline NG226 on osteoarthritis, which advises considering intra-articular corticosteroid injections when other treatments are ineffective or unsuitable or to support therapeutic exercise, and explicitly frames the benefit as short-term relief of two to ten weeks; the 2017 randomised trial in JAMA of intra-articular triamcinolone against saline over two years in knee osteoarthritis; and the LEAP randomised trial in the BMJ comparing exercise, injection and a wait-and-see approach in gluteal tendinopathy. Evidence checked in August 2026.
Two honest limits. The evidence here is strongest for the knee and the lateral hip and thinner at other sites, and injection technique, drug, dose and use of ultrasound guidance all vary between clinicians in ways trials do not fully capture.
No costs are quoted, because prices were not verified for this review. What private physiotherapy costs in East Sussex covers the rehabilitation side separately.
Ask what the window is for. An injection with a rehabilitation plan attached is a different proposition from an injection on its own. If nobody has mentioned what happens in weeks two to ten, that is the question to ask.
Ask whether pain is genuinely the blocker. Injections earn their place when pain is preventing the exercise that would help. Where the exercise is achievable already, the injection adds less.
Count the previous ones. How many, into which joint, and how long each lasted. A shortening pattern of relief is informative.
Ask about the specific joint. The evidence is not uniform. The lateral hip is the clearest case where injection underperforms exercise at one year.
Check the diagnosis is settled. Injecting a joint before knowing what is wrong with it converts a diagnostic question into a temporary answer.
What it is
A corticosteroid, often with local anaesthetic, injected into a joint or the tissue around it. The steroid is a potent anti-inflammatory that acts locally, and the anaesthetic gives immediate but brief numbness.
What to expect
The anaesthetic wears off within hours. The steroid takes two to seven days to take effect. The relief is variable in size and duration, and NICE frames it as short-term, in the region of two to ten weeks.
What the evidence supports
NICE advises considering intra-articular corticosteroid injections when other pharmacological treatments are ineffective or unsuitable, or to support therapeutic exercise, and states that they provide short-term relief only. The evidence review behind it found inconsistent benefits and no evidence of benefit beyond three months.
Limits and cautions
The phrase to support therapeutic exercise is the important part. The guidance frames it as an aid to treatment rather than a treatment.
Why it ranks first
Expecting a cure and getting ten weeks is a poor experience. Expecting ten weeks and using them well is a good one, and the difference is entirely in what was explained beforehand.
What it is
An increase in pain in the first 24 to 48 hours after the injection, sometimes marked, as the local anaesthetic wears off and before the steroid begins working. It is a recognised and common reaction.
What to expect
Pain returning within a few hours of leaving, often worse than beforehand, settling over one to two days. Ice, simple pain relief and relative rest for that period. Then a gradual improvement over the following week.
What the evidence supports
Post-injection flare is a well-described reaction, sometimes attributed to crystallisation of the steroid preparation within the joint. It is self-limiting and does not indicate a failed injection.
Limits and cautions
There is one situation that is not a flare. A joint that becomes increasingly hot, red and swollen after 48 hours, particularly with fever or feeling unwell, could indicate a joint infection, which is rare and serious. That needs same-day medical assessment rather than waiting.
Why it ranks second
It happens to a substantial minority, it happens before anything good does, and people who were not warned conclude the injection has made things worse and lose confidence in the plan.
What it is
The period of reduced pain during which loading, strengthening and range work can be done that was not possible before.
What to actually do
Rest for the first 48 hours, then start. Progressive strengthening for the muscles around the joint, range work, and a graded return to the activities that had been dropped. Two to three sessions a week through the whole window, with the aim that capacity is higher at week ten than it was at week one.
What the evidence supports
NICE positions injections as a way to support therapeutic exercise, and this is the practical meaning of that phrase. Exercise is what produces durable change; the injection makes it possible when pain has been the obstacle.
Limits and cautions
The reduced pain can allow you to do more than the tissue is ready for, particularly in a tendon. The absence of pain is not proof of capacity, so progress by plan rather than by how it feels.
Why it ranks third
It is the only item on this list that changes anything after week ten, and it is the one most often left out of the conversation entirely.
The question
Whether having injections repeatedly, over years, does harm.
What the evidence supports
The 2017 JAMA trial randomised 140 people with symptomatic knee osteoarthritis to intra-articular triamcinolone or saline every three months for two years. The steroid group had significantly greater cartilage volume loss than the saline group, and there was no significant difference in knee pain between the two. That is an unfavourable result on both counts: more structural loss, and no pain benefit over placebo across the trial period.
How to read it
This tested a specific regimen, four injections a year for two years into an osteoarthritic knee. It does not establish that a single injection, or an occasional one, causes harm. It does argue strongly against injections on a fixed schedule as a long-term management strategy.
Limits and cautions
Practice commonly limits injections into the same joint to around three or four a year and often fewer, with intervals of at least three months. Other recognised effects include skin thinning and loss of pigment at the injection site, a temporary rise in blood sugar that matters for people with diabetes, and tendon weakening where steroid is placed close to a tendon.
Why it ranks fourth
It changes the decision about the second, third and fourth injection rather than the first, which is where most people find themselves after a couple of years.
The situation
Cases where an injection performs worse than the alternative, or where it treats the wrong thing.
What the evidence supports
The clearest example is gluteal tendinopathy at the outer hip. In the LEAP trial, education plus exercise outperformed corticosteroid injection at eight weeks, with 77% at least moderately better against 58%, and the gap remained at one year, with around 80% successful in the exercise group against roughly half in the injection group. Injection also beat doing nothing, so it is a question of what it is being compared against.
Other situations to think twice about
Where the diagnosis is not settled, since an injection converts a diagnostic question into temporary relief. Where infection is possible. Where an exercise programme has never genuinely been tried. Around a weight-bearing tendon such as the Achilles, where steroid is generally avoided because of rupture risk.
Limits and cautions
There are also situations where an injection is clearly reasonable: severe pain preventing sleep, a joint too painful to begin rehabilitation, a specific event to get through, or a flare of inflammatory arthritis in a single joint.
Why it ranks fifth
It is the point that decides whether to have one at all, and it makes the most sense once the four points above are understood.
| Consideration | Steroid injection | Progressive exercise | Both together |
|---|---|---|---|
| Pain relief in the first month | Good | Limited, sometimes worse | Good |
| Result at 12 months | Limited | Good | Best where pain was the blocker |
| Changes joint capacity | No | Yes | Yes |
| Repeatable indefinitely | No | Yes | Yes |
| Risks | Flare, skin changes, raised blood sugar, rare infection | Temporary soreness | As for injection |
The first two rows explain most of the disappointment people report with injections. They perform well on the timescale over which the decision is made, and poorly on the timescale that actually matters, unless the third column is what happened.
If you have been offered an injection and no rehabilitation plan, ask what the plan is for weeks two to ten. That conversation is the difference between a good injection and a wasted one.
If your joint hurt more the day after, that is the recognised post-injection flare and it usually settles within 48 hours.
If a joint becomes hot, red and increasingly swollen more than 48 hours afterwards, with fever, seek same-day medical care. Joint infection is rare and it is urgent.
If you are on your third or fourth injection into the same knee, the JAMA trial is worth discussing with whoever is offering it, particularly if each one is lasting less time than the last.
If the problem is your outer hip and you have not done a loading programme, the trial evidence favours doing that first.
If pain is stopping you sleeping or starting any rehabilitation at all, this is exactly the situation an injection is for.
The belief that arrives most often is that the injection is the treatment and physiotherapy is what you try if it does not work. That order is backwards, and it is understandable, because the injection is the thing with the dramatic effect and it happens first.
What testing shows in the weeks afterwards is fairly consistent. A knee that is pain free at week three is frequently no stronger than it was at week zero, because the quadriceps has been shutting down for two years and eight weeks of comfort does not reverse that on its own. When the steroid wears off, the same joint meets the same demands with the same muscle behind it, and the result is the same pain plus the conclusion that injections do not last. They do not last; they were never going to. What lasts is what got built while they were working.
Where an injection is planned or has just been done and the window needs using properly, that is what the musculoskeletal pain and injuries service is for.
How long does a steroid injection last for joint pain?
NICE describes the relief as short-term, in the range of two to ten weeks, with no evidence of benefit beyond three months. The response varies widely between people and between joints, and the guidance frames the injection as a way to support therapeutic exercise rather than as a treatment on its own.
Why does my joint hurt more after a steroid injection?
This is a post-injection flare and it is common. The local anaesthetic wears off within hours while the steroid takes two to seven days to work, so there is a gap during which pain returns and can be worse than before. It usually settles within 24 to 48 hours with ice and simple pain relief.
Do steroid injections damage cartilage?
A 2017 randomised trial in JAMA gave people with knee osteoarthritis an injection every three months for two years and found significantly greater cartilage volume loss than with saline, with no pain benefit. That argues against injections on a fixed long-term schedule. It does not establish that a single or occasional injection is harmful.
How many steroid injections can you have in one joint?
Practice commonly limits injections to around three or four a year into the same joint, and often fewer, with at least three months between them. The more useful question is what changed after the last one, since a pattern of progressively shorter relief suggests the underlying problem is not being addressed.
What should I do after a steroid injection?
Rest relatively for the first 48 hours through the possible flare, then begin the rehabilitation the injection was meant to enable: progressive strengthening and range work, two to three sessions a week, through the whole window of reduced pain. Progress by plan rather than by how the joint feels, because reduced pain is not the same as increased capacity.
Is exercise better than a steroid injection?
For gluteal tendinopathy at the outer hip, yes. The LEAP trial found education plus exercise beat injection at eight weeks and was still well ahead at one year. For other conditions the answer depends on whether pain is preventing exercise, which is the situation injections are best suited to.
When should I not have a steroid injection?
When the diagnosis is not yet settled, when infection is possible, when a proper exercise programme has never been tried, and around weight-bearing tendons such as the Achilles where steroid is generally avoided because of rupture risk. People with diabetes should also know that blood sugar commonly rises for several days afterwards.
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