Reactive arthritis is a type of inflammatory arthritis that develops after an infection elsewhere in the body, most often in the gut or the genital and urinary tracts. Joint pain and swelling, typically in the knees, ankles, or feet, usually begin one to four weeks after the infection, and the condition often clears on its own within about six months. It isn’t contagious, it isn’t anyone’s fault, and most people recover.
If you’ve recently had food poisoning, a urinary or genital infection, or another illness and now have sore joints, red eyes, or other symptoms that seem to come out of nowhere, this guide will help you make sense of what’s happening. It explains what reactive arthritis is, what causes it, what the symptoms look like, how it’s treated, and what to expect, in a way that’s meant to be calm, clear, and free of judgment.
Quick Facts About Reactive Arthritis
Here’s the short version before we go deeper.
- What it is: Inflammation in the joints (and sometimes eyes, skin, and urinary tract) triggered by an infection elsewhere in the body.
- Who gets it: Most often adults in their 20s to 40s, though anyone can develop it. People who carry a gene called HLA-B27 are more likely to.
- Timing: Symptoms typically start one to four weeks after the infection, which may have been mild or unnoticed.
- Contagious? No. The infection that triggered it may be passed on, but the arthritis itself is not.
- Treatment: Anti-inflammatory medicines, sometimes steroid injections, physical therapy, and treatment of any ongoing infection. Stronger medicines are used for stubborn cases.
- Outlook: Most people recover within about six months. Some have flare-ups later or develop longer-lasting arthritis, and doctors can help manage that.
What Is Reactive Arthritis?
A 2021 clinical review in the Journal of the Royal College of Physicians of Edinburgh describes reactive arthritis as a form of inflammatory arthritis triggered by a remote infection, typically in the gastrointestinal or genitourinary systems. It belongs to a family of conditions called spondyloarthropathies, which can involve the spine, joints, tendons, and sometimes the eyes and skin.
The name can be confusing. “Reactive” means the joints are reacting to an infection that happened elsewhere. In most cases, there are no live germs in the joint itself. Instead, the immune system, which was activated to fight the infection, keeps up its inflammatory response in places it shouldn’t. That’s different from septic arthritis, where a joint is directly infected and needs urgent care, a distinction we’ll return to in the section on when to get help.
You may also see the older name “Reiter’s syndrome” in older articles. Most doctors now use “reactive arthritis” because it describes what’s actually happening.
What Causes Reactive Arthritis?
Reactive arthritis starts with an infection, but not everyone who has that infection will develop arthritis. The usual story involves three ingredients: a triggering infection, a specific immune response, and often a genetic predisposition.
Infections in the Gut
Stomach bugs and food poisoning are common triggers. These include Salmonella, Shigella, Campylobacter, and Yersinia. Cooking food thoroughly, washing hands, and storing food safely lower your risk of these infections, but they can still happen even in the cleanest kitchens and restaurants, so there’s nothing to blame yourself for if one of them led to this.
Infections in the Genital and Urinary Tract
Chlamydia is the best-known trigger. Chlamydia is very common and treatable. Having had it, or any infection, says nothing about your character, and doctors treat reactive arthritis after a sexually acquired infection as a medical complication, not a moral one.
The 2021 guidance from the British Association for Sexual Health and HIV is a good example, describing it plainly as a sterile inflammation triggered by an infection at a distant site and recommending the same multidisciplinary care you would expect for any other medical condition.
Other Infections, Including COVID-19
Other infections have been linked to reactive-type arthritis in case reports. A 2021 case-based review in Rheumatology International described arthritis after COVID-19, including a patient who developed a single swollen joint and responded well to a standard anti-inflammatory medicine. These reports are interesting to researchers, but they describe a small number of people. If you’ve had COVID-19 and have joint pain, it doesn’t mean you have a serious problem, but it’s reasonable to mention it to your doctor if it lingers.
The Role of Genes
A gene called HLA-B27 is more common in people with reactive arthritis. Harvard Health notes that up to 60% of people with reactive arthritis carry it, compared with about 8% of the general population. Carrying the gene doesn’t mean you’ll get the condition, and many people with reactive arthritis don’t have it. Doctors may use the test as a clue, and the clinical review above notes that HLA-B27 can support a diagnosis in the right setting and is also a marker for how the condition might behave over time.
How Common Is Reactive Arthritis?
It’s uncommon, and that’s a helpful fact to hold onto if you’re worried. The most useful recent numbers come from a 2024 systematic review and meta-analysis in the Journal of Clinical Medicine, which covers 87 studies on reactive arthritis after gut infections. It estimated that reactive arthritis developed in about:
- 3% of people after Campylobacter infection
- 4% after Salmonella
- 1% after Shigella
- 5% after Yersinia
- 1% after E. coli
The authors cautioned that results varied widely across studies, so the exact figures are rough estimates. But the overall picture is consistent: the large majority of people who get a stomach infection never develop reactive arthritis.
For sexually acquired infections, the BASHH guidance notes that the incidence of sexually acquired reactive arthritis has declined even as chlamydia diagnoses have risen, which may reflect earlier detection and treatment. It is reported more often in men, by a ratio of more than 10 to 1, but people of any gender can be affected.
What Are the Symptoms of Reactive Arthritis?
Symptoms usually appear one to four weeks after an infection, and they can come and go. Not everyone has all of them. In fact, many people have only a few.
Joint Symptoms
The hallmark is pain, swelling, and stiffness in the joints, typically in an asymmetric pattern, meaning it doesn’t affect both sides equally. The knees, ankles, and feet are the most common spots. Back pain and stiffness, especially in the morning or at night, can also occur when the sacroiliac joints at the base of the spine are involved.
Tendon and Heel Pain
Inflammation where tendons and ligaments attach to bone, called enthesitis, can cause heel pain or pain at the bottom of the foot. Some people have a “sausage digit,” a toe or finger that swells along its whole length, known as dactylitis.
Eye Symptoms
Red, irritated, or gritty eyes (conjunctivitis) are common and usually mild. Less commonly, deeper eye inflammation called uveitis can develop, causing pain, light sensitivity, and blurred vision. This one needs prompt attention from an eye specialist, so don’t wait it out.
Urinary and Genital Symptoms
Some people notice burning when they urinate, a more frequent need to go, or discharge. These can come from the original infection or from inflammation of the urethra that follows it.
Skin and Mouth Changes
Mouth ulcers, a rash with small pustules on the soles of the feet, or thickened skin can occur. These can look alarming, but they’re a recognized part of the condition and often fade as the inflammation settles.
Fatigue and Other Whole-Body Symptoms
Tiredness, a low fever, and general aches are common, particularly early on. Fatigue can linger and is often the most frustrating symptom.
Is Reactive Arthritis Contagious?
No. You can’t catch reactive arthritis from someone, and you can’t pass it to anyone. Underlying infections that trigger it, such as food poisoning or sexually transmitted infections, may be transmissible, but the joint condition itself is not.
If your trigger was a sexually transmitted infection, your clinician will likely talk with you about informing recent partners so they can get tested and treated if needed. The BASHH guidance describes this as a standard, routine part of care, not a judgment. It protects everyone’s health, including yours, by lowering the chance of reinfection.
How Is Reactive Arthritis Diagnosed?
There’s no single test that confirms it. Diagnosis relies on putting several pieces together, which can take time, especially since symptoms often appear at different times.
Doctors consider your history of infection, your symptoms, a physical exam, and sometimes imaging and joint fluid analysis. The Merck Manual says testing is also used to rule out similar disorders.
Your doctor may also check for the trigger infection, such as testing for chlamydia or a stomach infection, and may order the HLA-B27 blood test. A normal result for one test doesn’t rule it out. It’s common to need a few visits, and a rheumatologist, a doctor who specializes in arthritis and related conditions, often helps.
Getting a diagnosis can feel slow. The lack of a single test makes this one of the conditions where it helps to keep a symptom diary and note when things started and any infection beforehand.
What Are the Treatment Options?
Treatment has two goals: to ease symptoms and, if needed, to address any lingering infection.
Anti-Inflammatory Medicines
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen are usually the first step, and the BASHH guidance also lists them as first-line. Steroids, either as injections into a particularly swollen joint or as tablets for a short time, may help when NSAIDs aren’t enough. Always check with a doctor or pharmacist about which medicines are safe for you, especially if you have stomach, kidney, heart, or blood pressure concerns, or take other medicines.
Antibiotics: When They Help and When They Don’t
Antibiotics are prescribed when there’s a current infection to treat, such as chlamydia. The BASHH guidance is careful on this point. Antibiotics are essential for identified infections, but whether they help the arthritis itself “is controversial,” and longer-term antibiotic therapy hasn’t been proven. In other words, if your doctor treats your infection but doesn’t prescribe a long course for your joints, that’s evidence-based care, not neglect.
Disease-Modifying Medicines and Biologics
If symptoms last for months or are severe, a rheumatologist may recommend disease-modifying antirheumatic drugs (DMARDs), such as sulfasalazine or methotrexate, or biologic medicines. Some people with a chronic course need this type of immune-modulating therapy.
Physical Therapy
Physiotherapy helps keep joints moving, prevents muscle loss, and can ease stiffness. The BASHH guidance specifically mentions it for preventing muscle wasting and improving function.
Eye and Skin Care
If your eyes or skin are involved, an ophthalmologist or dermatologist may join your care team. Eye symptoms in particular should be assessed quickly.
How Long Does Reactive Arthritis Last?
For most people, it’s a temporary condition. It usually goes away within six months, although it can last longer in some people.
It helps to be clear-eyed about the less common outcomes too, without letting them loom larger than they should.
- Recurrence: Some people have flare-ups after the first episode. Estimates of recurrence vary widely.
- Longer-lasting arthritis: A smaller group, often estimated at 15% to 30%, develops longer-term joint problems that need ongoing management.
- Higher-risk features: Carrying HLA-B27 and certain triggers, including chlamydia, are associated with a higher chance of persistent symptoms.
These numbers come with real uncertainty because studies differ in how they define and follow cases. What they show is that most people recover, and for those who don’t, effective treatments exist, and early care helps.
Reactive Arthritis Without Shame
Reactive arthritis sits at a crossroads of things people feel awkward about, such as stomach illness, sexual health, and chronic pain. That can make it hard to ask questions or even tell your doctor the whole story. A few things deserve to be said:
- Infections are part of being human. Food poisoning, urinary infections, and sexually transmitted infections happen to people of every age, background, and relationship status, often with no symptoms. Financial, medical, and educational accessibility all play a role in your overall health.
- The trigger infection may have been mild or unnoticed. The NHS notes the original infection can be so mild it goes unnoticed, so you may never know what started it.
- Telling your doctor the full story is protective. Clinicians treat this like any other medical condition. Sharing recent infections, partners, and symptoms isn’t an admission of anything. It helps you get the right tests and treatment faster.
- Your arthritis isn’t a punishment. Immune systems react to infections in different ways, and genetics play a role. Who develops reactive arthritis isn’t a measure of how careful, clean, or responsible someone is.
- If you’re worried about privacy, you can ask about confidentiality. You can ask any clinician or clinic how they keep your information confidential before you share details.
If you carry shame about any part of this, you deserve care without it.
Living With Reactive Arthritis: Practical Tips
While your body works through this, these steps can make daily life easier. They support your treatment but don’t replace advice from your own care team.
- Keep gently moving. Rest during bad flares, but light movement and stretching, ideally guided by a physiotherapist, help prevent stiffness.
- Pace yourself. Fatigue is common. Spread tasks across the day and build in breaks without guilt.
- Use heat or cold. Many people find that warmth helps with morning stiffness, and cold packs ease a hot, swollen joint.
- Track your symptoms. Note joint pain, eye changes, urinary symptoms, and fatigue. It helps your doctor see patterns.
- Protect your sleep. Pain can disrupt sleep, which in turn can worsen pain and mood. Mention persistent sleep trouble to your doctor.
- Look after your mind. Ongoing pain and uncertainty can wear on anyone. If anxiety or low mood is building, talking with a therapist or doctor is a sign of good self-care, and many people with chronic conditions benefit from it.
- Ask about work and school adjustments. Flexible hours, a supportive chair, or short breaks can make a real difference while you recover.
When to Get Medical Help
Most symptoms can be handled with a routine appointment, but a few need faster attention.
Seek urgent help (call your local emergency number or get same-day care) for:
- A single joint that suddenly becomes severely painful and swollen
- Hot, red skin over a joint
- Joint pain along with fever
- Joint pain along with eye problems, such as pain, light sensitivity, or blurred vision
- Joint pain along with urinary symptoms
- Pain that over-the-counter medicine can’t control
Fever with a hot, swollen joint can sometimes signal a joint infection, a different condition that requires urgent treatment. It’s far better to be checked and reassured than to wait.
Book a routine appointment if:
- You have swollen, painful joints that are unusual for you
- Symptoms haven’t improved after a few weeks
- Symptoms keep coming back
A Comforting Note for Anyone Feeling Anxious About This
If you’ve been searching symptoms and feeling your heart race, take a moment. Reactive arthritis is uncommon, and most people who get it improve within months. Joint pain after an infection doesn’t automatically mean you have something serious or permanent, and it isn’t the same as rheumatoid arthritis. Many people feel better and go on to live their lives as usual.
If a recent infection brings up guilt or embarrassment, please set that down. You didn’t do anything to cause this. Infections happen to nearly everyone, and how the immune system reacts afterward is largely beyond anyone’s control. Getting medical care is not a confession. It’s a reasonable step toward feeling better.
And if you’re in the middle of a flare right now, with sore joints, a tired body, and worries on top of it all, you’re allowed to rest. Uncertainty is hard, especially when diagnosis takes time. It helps to remember that doctors know this condition well, that treatments exist, and that you don’t have to figure it out alone. Take it one appointment at a time.
Frequently Asked Questions
What is reactive arthritis in simple terms?
It’s joint inflammation that happens after an infection elsewhere in the body, usually in the gut, genital tract, or urinary tract. The joints are reacting to the infection rather than being infected themselves.
What are the first signs of reactive arthritis?
Often it begins with pain and swelling in a knee, ankle, or foot one to four weeks after an infection. Red eyes, burning when urinating, heel pain, rashes, and tiredness can also appear.
Is reactive arthritis curable?
For most people, it resolves on its own, usually within about six months, with treatment to ease symptoms. Some people have flare-ups or longer-lasting arthritis, which doctors can manage with stronger medicines.
Is reactive arthritis an STI?
No. It isn’t a sexually transmitted infection and can’t be passed on. It can follow one, such as chlamydia, but it can also follow food poisoning and other infections.
Can stress cause reactive arthritis?
Reactive arthritis is triggered by infection, not by stress. Stress can make pain, sleep, and mood feel harder to manage, so looking after your wellbeing is still a helpful part of recovery.
Is reactive arthritis the same as rheumatoid arthritis?
No. They’re different conditions. Reactive arthritis follows an infection and often involves the lower limbs, eyes, and urinary tract, while rheumatoid arthritis is a long-term autoimmune condition that typically affects joints on both sides of the body.
Should I see a doctor if I think I have it?
Yes. Joint swelling that’s unusual for you warrants a medical check, and anything severe, hot, red, or accompanied by fever, eye symptoms, or urinary symptoms needs urgent attention. Early care helps rule out other causes and get you comfortable sooner.