Glossary
Flare
Fear of causing a flare is one of the main reasons people with autoimmune disease avoid exercise. Several trials counted the flares that happened. The counts came back zero.
What the research found.
A Cochrane review pooled 13 randomized trials of exercise in lupus, and it recorded zero flares and zero serious harm. Tiredness improved by 6.3 points, against the 5.9 points that counts as a difference a patient would notice. So the trials weren't inert while nothing bad happened in them.
Frade and colleagues, Cochrane Database of Systematic Reviews, 2023
One 16-week trial took 45 women with Sjogren syndrome who never exercised, and half got supervised walking while half got no regular exercise. It reported no flares and no serious harm. In the walking group, 95.4 percent said they felt better overall, against 62 percent of the others.
One randomized trial gave talking therapy to 45 lupus patients under high daily stress, and it counted flares among the things it watched. It found no real change in any immune measure. The patients' mood scores and quality of life did improve.
Navarrete-Navarrete and colleagues, Psychotherapy and Psychosomatics, 2010
One study asked 313 adults with inflammatory arthritis about their sleep, where the disease was mostly quiet or nearly quiet. Even so, 63.7 percent with rheumatoid arthritis slept badly. In psoriatic arthritis it was 61.5 percent, and in axial spondyloarthritis it was 66.7 percent.
What the word means, and how loosely
A flare is a stretch when your disease gets more active than usual, and that definition is vague because the vagueness is real rather than a dodge. Research definitions differ by disease and by study, where some use a change in a combined score, some use a doctor's judgment, and some use whether the treatment had to be stepped up. There isn't one agreed line.
This site holds no source comparing those definitions, so which one your rheumatology team works from is a question only they can answer. Asking is fair, and the answer decides what they want you to report and when. A person and a protocol can mean quite different things by one word.
What all the definitions share is that they describe activity rather than experience, which is the same split that makes remission a measurement rather than a feeling. Somebody can feel dreadful without meeting any flare definition. The reverse happens too.
The fear that keeps people still
The most useful evidence on this page isn't about what a flare is. It's about one specific fear, which is that many people with autoimmune disease avoid exercise because they expect it to set one off. That expectation has been tested, and it didn't hold up.
A Cochrane review pooled 13 randomized trials of exercise in lupus, and across all of them it recorded zero flares and zero serious harm. The trials weren't inert either, because tiredness improved by 6.3 points, against the 5.9 points that counts as a difference a patient would notice. How much people could do improved too, and so did quality of life.
A separate 16-week trial took 45 women with Sjogren syndrome who never exercised and put half into supervised walking three times a week, while the other half were asked to avoid regular exercise. It reported no flares and no serious harm. In the walking group, 95.4 percent said they felt better overall, against 62 percent of the others.
What those trials do and don't settle
Zero flares across 13 trials is a strong safety signal, and it still isn't a personal guarantee about you. Trial patients get picked and supervised. Their disease is usually stable by the time they enroll, so somebody in the middle of severe active disease is not who those trials were studying.
What the evidence does is move the burden of proof. The claim that exercise is risky by nature in autoimmune disease has been tested again and again and hasn't held, so it shouldn't be the automatic reason behind a decision to stay still. Losing fitness has its own costs, and those pile up over years.
Feeling worse after unfamiliar effort is a separate event from a disease flare, and telling the two apart is most of the practical difficulty here. Sore muscles and tiredness after a new activity happen to everybody. So what the trials settle is that the disease itself didn't get worse, and they don't settle that nothing ever aches.
Why this page has no trigger list
The one thing most people searching this word want is a list of what causes flares. This site holds no source on flare triggers at all, so no list appears here, and that absence is worth naming rather than papering over. It's a limit on what we can say rather than a claim that nothing sets one off.
Trigger lists go around widely and most of them are unsourced, with specific foods blamed, and weather conditions, and activities. That blame usually rests on one person matching two things up in their own life, which is how a coincidence turns into an established fact. So ask where a figure or a claim came from, and if the answer is nowhere, that's worth knowing.
One thing close to a trigger has been tested here. A randomized trial gave talking therapy to 45 lupus patients under high daily stress and watched both flares and immune measures, and the therapy improved their mood scores and their quality of life. Its authors say they found no real change in any immune measure, so the trial backs stress work for what it does deliver rather than as flare prevention.
Why a bad week isn't automatically a flare
Feeling terrible fits perfectly well with a controlled disease, which is one of the more disorienting features of these illnesses. One study asked 313 adults with inflammatory arthritis about their sleep, where the disease was mostly quiet or nearly quiet, and 63.7 percent with rheumatoid arthritis still slept badly. In psoriatic arthritis it was 61.5 percent and in axial spondyloarthritis 66.7 percent, so about two in three people with a controlled disease were sleeping badly.
That study looked at people at one moment, so it describes symptoms sitting alongside controlled disease rather than showing one causing the other. What it does argue is that a run of bad days needs reporting rather than interpreting. Telling a flare from everything else is a call your team is better placed to make than you are, and they need your symptoms to make it.
The reverse mistake costs more than this one does. Write off rising symptoms as a bad week and you delay a response you may need. Three things produce the identical feeling, which are an infection, a missed or reduced dose, and plain variation in the illness, so changing your own medication before that conversation throws away the information needed to tell them apart.
Common misconceptions.
Myth. Exercise will trigger a flare.
Reality. The trials that counted them say otherwise. A Cochrane review pooled 13 randomized trials of exercise in lupus and recorded zero flares and zero serious harm, and a 16-week walking trial in Sjogren syndrome reported none either. Those patients were supervised and their disease was mostly stable, so this isn't a guarantee for every situation. It does move the burden of proof, though, and the claim that exercise is risky now has to earn its keep.
Myth. A flare means my treatment has failed.
Reality. It means your disease activity rose, and that can happen for reasons that have nothing to do with a drug wearing off. An infection can do it, a missed dose can do it, and so can plain variation in the illness. So a flare should start a conversation with your team rather than a change you make alone, because the right response depends on which of those explanations fits you.
Myth. I can tell a flare from a bad week.
Reality. Sometimes, and the two overlap more than most people expect. About two in three adults with inflammatory arthritis slept badly even when their disease was quiet, so feeling terrible fits perfectly well with a controlled score. That's a reason to report your symptoms rather than diagnose yourself, in either direction, because the answer changes what should be done about it.
Myth. Managing stress will stop my flares.
Reality. One randomized trial tested that, giving talking therapy to lupus patients under high daily stress and watching both flares and immune measures. The therapy did improve their mood scores and their quality of life. Its authors say they found no real change in any immune measure at all, so stress work is worth having for what it does deliver, and this trial doesn't back it as a way to stop flares.
Related terms.
- Remission, the state a flare is defined against.
- DAS28, the composite score some flare definitions are built on.
- Lupus and exercise, for the Cochrane review in full.
- Sjogren's and exercise, for the walking trial in full.
Questions patients ask.
What counts as a flare?
A rise in disease activity above your usual level, and that sounds vague because the research definitions really do differ. They differ by disease and they differ by study, where some use a change in a combined score, some use a doctor's judgment, and some use whether the treatment had to be stepped up. This site holds no source comparing those definitions, so it can't tell you which one your own team works from.
Will exercise cause a flare?
The trials that counted found none at all. A Cochrane review pooled 13 randomized trials of exercise in lupus and found zero flares and zero serious harm, and a 16-week supervised walking trial in Sjogren syndrome reported none either. In that one, 95.4 percent of the walkers said they felt better overall, against 62 percent of the others. Those patients were supervised and their disease was mostly stable, so the finding is reassuring rather than absolute.
Then why does exercise sometimes make me feel worse?
Feeling worse after unfamiliar effort isn't the same event as a disease flare, and telling those two apart is most of the difficulty here. Sore muscles and tiredness after a new activity happen to people with no autoimmune disease at all. So what the trials settle is that the disease itself didn't get worse, and they don't settle that nothing ever aches.
What triggers a flare?
This site holds no source on flare triggers, so no list appears here, and that's an honest limit rather than a hint that nothing sets off a flare. If you read something blaming flares on a specific food, or on the weather, or on an activity, ask where that claim came from before you rearrange anything. Trigger lists that sound right go around widely with nothing behind them.
Can stress management prevent flares?
One trial tested something close to that, giving talking therapy to 45 lupus patients under high daily stress. Their mood scores improved and so did their quality of life. Its authors report no real change in any immune measure they took, so that backs stress work for how people feel and function rather than as a way to stop flares.
What should I do when I think I'm flaring?
Report it rather than deciding what it means, because the useful responses differ. Three things all produce rising symptoms, which are an infection, a missed or reduced dose, and plain variation in the illness, and the right action differs for each one. So if you change your own medication before that conversation, you throw away the information your team needs to tell them apart.
Is a flare the opposite of remission?
Broadly yes, because the two words sit at opposite ends of one idea, and that idea is measured disease activity. Remission means activity below a set line and a flare means a rise above your usual level. Neither one describes how well you feel, which is why people in remission still have bad weeks and why a bad week isn't automatically a flare.
References.
- Frade S; O'Neill S; Greene D et al. Exercise as adjunctive therapy for systemic lupus erythematosus. The Cochrane database of systematic reviews. 2023;4:CD014816. 10.1002/14651858.CD014816.pub2Cochrane SR
- Miyamoto S; Valim V; Carletti L et al. Supervised walking improves cardiorespiratory fitness, exercise tolerance, and fatigue in women with primary Sjögren’s syndrome: a randomized-controlled trial. Rheumatology International. 2019;39:227-238. 10.1007/s00296-018-4213-zRandomised controlled trial
- Navarrete-Navarrete N; Peralta-Ramírez M; Sabio-Sánchez J et al. Efficacy of Cognitive Behavioural Therapy for the Treatment of Chronic Stress in Patients with Lupus Erythematosus: A Randomized Controlled Trial. Psychotherapy and Psychosomatics. 2010;79:107-115. 10.1159/000276370Randomised controlled trial
- Polak D; Kolasińska M; Wilk M et al. Sleep disorders in RA, axSpA and PsA are common despite good disease activity control—direct comparison of sleep quality and its risk factors using MDHAQ and PSQI. Clinical Rheumatology. 2026;45:957-965. 10.1007/s10067-025-07892-0Cross-sectional study of 313 adults from the PolNorRHEUMA registry: RA n = 129
This page gathers the published research on this subject into one place. The studies behind it were published between 1989 and 2026, and every figure links to the paper it came from. Those studies were peer reviewed. This summary of them was not. Dr. Sarah Luebker is reviewing these pages one at a time and has not reached this one yet, so it carries no medical review date and nothing here is her opinion or her advice to you. Each page gets updated as she reaches it. It is here in the meantime because the science is worth having in one organized place that is easy to find and easy to read. Talk to your own clinician before acting on any of it.