FLARES

When you flare: how to rest without losing ground

A flare is a reason to modify what you do, not usually a reason to stop everything, and knowing the difference protects you both ways.

Week of September 4, 2026. Angelo Papachristos PT, ACPAC. RheumAcademy | Arthros Inc.

A woman in her fifties with rheumatoid arthritis came in with her phone open to her step count. It showed a flat line for ten days. Her hands and knees had flared, she told me, so she had stopped her morning walks and mostly stayed on the couch, and now she was stiffer than before and frightened that she had either made the arthritis worse by moving earlier, or made her body worse by stopping. She wanted one clear rule: when a flare hits, do I push through or do I stop.

First, what a flare actually is

A flare is a period where your symptoms get worse than your usual baseline, badly enough that you would change what you do about it. That is roughly how patients and clinicians landed after the OMERACT flare work led by Bykerk and colleagues, who found that patients describe a flare not as a single sore joint but as a cluster: more pain, more swelling, more stiffness, more fatigue, and the sense of not coping. Worth holding onto because it means fatigue and a foggy, wiped-out day are part of a flare, not you being weak.

Here is the distinction that changes what you do. A true disease-activity flare is your immune system turning the inflammation up: joints that are warm and puffy, morning stiffness that stretches past an hour, several joints at once, sometimes a low fever or feeling systemically unwell. A symptom spike is your body being sensitive on a bad day: you overdid the garden, you slept badly, you are stressed, you have a cold, the barometric pressure dropped. Both hurt. They are not the same problem, and they do not call for the same response. The Cloudy with a Chance of Pain study, a UK smartphone study by Dixon and colleagues in 2019 that tracked more than 2,600 people, found that damp, low-pressure days were modestly more painful for people with long-term pain conditions, a link that held even after accounting for mood and activity. That is real, but a weather-driven bad day is a spike, not your disease escaping control.

The rest question, answered properly

The instinct to shut everything down during a flare is understandable and mostly wrong. Complete rest for days at a time costs you quickly. Muscle strength, joint range, and cardiovascular fitness all fall off faster than people expect, and for someone with arthritis that deconditioning becomes its own source of pain and stiffness, which is exactly the trap my patient walked into over her ten flat days.

What you want is relative rest. You lower the load, you do not remove it. The 2018 EULAR physical activity recommendations, led by Rausch Osthoff, were built on trial evidence across inflammatory arthritis and osteoarthritis and reached a plain conclusion: regular physical activity is safe and effective, and belongs in standard care throughout the course of these diseases. The Cochrane review of dynamic exercise in RA by Hurkmans and colleagues found that structured aerobic and strengthening programs improved aerobic fitness and strength, with no harmful effect on disease activity or joint damage in any of the trials it reviewed. Movement does not switch your disease on. Your immune system drives the flare. So the fear that continuing to move 'caused' it is almost always misplaced.

There is one honest exception. A single joint that is hot, tensely swollen, and far more painful than everything else, especially with a fever, is not the joint to exercise or wait out. That picture can be a joint infection, and in someone on immune-suppressing treatment it is an emergency, not a flare to manage at home. Steroids and some biologics can blunt a fever, so a single hot, tensely swollen joint still warrants the same-day call even when your temperature is normal.

Modify, don't quit

Modifying is a set of dials, not an on-off switch. Drop the intensity before you drop the activity. If your usual walk is thirty minutes, do ten, twice, on flat ground. Swap impact for water or a bike. Keep joints moving through comfortable range even if you cannot load them, because range is the first thing you lose and the most miserable to win back. Reduce the weight and keep the movement pattern. Let sore hands do gentle open-and-close cycles rather than nothing.

Use pain as a guide, not a verdict. A useful rule from rehab practice is that a flare-up of symptoms during or after activity that settles back to your baseline within a day or so is acceptable, and pain that climbs higher each day or lingers well beyond the session means you have dialled too far up. That gives you permission to keep going through discomfort without ignoring a genuine warning. For my patient, the answer was not couch or full walk. It was a short, flat, daily loop she could hold through the flare so her knees and her fitness did not seize up while the inflammation settled.

Write it down so the visit is worth having

Most flares are described from memory weeks later, badly, and that wastes your appointment. Keep a simple flare log. Note the date it started and how long it lasted, which joints, whether they were swollen or just sore, your morning stiffness in rough minutes, your fatigue, whether you had a fever or felt unwell, and what was happening in your life. Add what you changed and whether it helped. A pattern of frequent or lengthening flares, or flares landing at the same point before your next biologic dose, is a treatment conversation, and your rheumatologist can only have it if you bring the record. This is also how you protect yourself against the opposite error, deciding your medication has failed off one rough fortnight when the fuller picture says your disease is mostly controlled.

When a flare is not a flare, and you call

Some things do not wait for your next appointment. One hot, intensely swollen joint out of proportion to the rest, particularly with fever or feeling unwell, needs a same-day call, because infection has to be ruled out before you assume arthritis. New chest pain or shortness of breath, a new severe headache, sudden painful red eye or vision change, and in lupus any new sign that could mean organ involvement such as marked swelling, frothy or blood-tinged urine, or new confusion, are all reasons to reach your team promptly rather than manage at home. A fever while you are on immune-suppressing treatment deserves a call even without a bad joint. None of this is meant to frighten you. It is meant to give you a short, memorable list so that the ordinary flares, which are the vast majority, stop feeling like emergencies.

What to do, and the conversation to have

When a flare hits, lower the load rather than stopping: cut intensity and duration, keep joints moving through comfortable range, and switch to low-impact if weight-bearing hurts. Judge it by whether symptoms settle back to baseline within a day; if they climb higher each day, ease off further. Keep a short flare log and bring it. And agree a flare plan and personal red-flag list with your care team ahead of time, so you already know what you can safely take, and which symptoms mean 'modify and keep moving' versus 'phone today.'

Questions for your care team

Which of my flare symptoms mean I should modify and keep moving, and which mean I should call you the same day?

Is the swelling I get between doses something my current treatment should be controlling, or is some of it expected before my next dose?

What is my personal urgent-call list, given my specific diagnosis and medications?

Between visits, can I bring a flare log (dates, joints, stiffness minutes, fatigue, fever, what I'd been doing) so we can see the pattern?

Should we agree a written flare plan now, including what I can safely take, when, and the point at which I should call rather than wait?

What this does not mean

A flare, on its own, does not mean your medication has failed or that you should stop it. Do not pause a DMARD or biologic during a flare without talking to your team, and do not treat a single rough week as proof your treatment isn't working.

References

Bykerk 2014 - OMERACT RA flare core domain set. Bykerk VP, et al. Establishing a core domain set to measure rheumatoid arthritis flares: report of the OMERACT 11 RA flare Workshop. J Rheumatol, 2014.
https://pubmed.ncbi.nlm.nih.gov/24584927/

Dixon 2019 - Cloudy with a Chance of Pain, weather and pain. Dixon WG, et al. How the weather affects the pain of citizen scientists using a smartphone app. npj Digital Medicine, 2019.
https://pubmed.ncbi.nlm.nih.gov/31667359/

Rausch Osthoff 2018 - EULAR physical activity recommendations. Rausch Osthoff AK, et al. 2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis. Ann Rheum Dis, 2018.
https://pubmed.ncbi.nlm.nih.gov/29997112/

Hurkmans 2009 - Cochrane dynamic exercise in RA. Hurkmans E, et al. Dynamic exercise programs (aerobic capacity and/or muscle strength training) in patients with rheumatoid arthritis. Cochrane Database of Systematic Reviews, 2009.
https://pubmed.ncbi.nlm.nih.gov/19821388/

This article is for education and is not a substitute for individual medical advice. Your diagnosis, medications, and personal risks change what the right response to a flare is, so use this to have a better conversation with your own rheumatology team rather than to make treatment decisions on your own.

Angelo Papachristos PT, ACPAC. Advanced Practice Physiotherapist. Co-Founder, RheumAcademy. Co-Founder, Arthros Inc.

Flares