Infrared Therapy and Arthritis: What Early Research Shows
Ask anyone living with arthritis what bothers them most day to day, and two words come up again and again: pain and stiffness. Whether it's the wear-and-tear of osteoarthritis or the immune-driven inflammation of rheumatoid arthritis, those two symptoms are what actually disrupt a morning, a workout, or a night's sleep.
Infrared heat is one of the older, better-studied tools people reach for alongside their medical care — it's a more targeted descendant of the heating pad, and researchers have been formally testing it against arthritis symptoms for well over a decade. That research base is genuinely encouraging in places. It's also still developing, with mixed results in some conditions and a real need for larger, longer trials. This guide walks through what the studies actually measured, what they found, where the evidence is thinner, and how infrared-based products fit into a broader arthritis routine.
What's Actually Happening in an Arthritic Joint
Arthritis isn't one disease — the term covers more than 100 conditions — but the two most common types get there through different routes.
Osteoarthritis is the wear-and-tear form. Over years of use, the cartilage that cushions the ends of bones gradually breaks down, and joints lose some of their smooth, frictionless movement. The Mayo Clinic and Cleveland Clinic describe this as the most common form, with pain, stiffness, and swelling concentrated in weight-bearing joints like the knees, hips, and spine.
Rheumatoid arthritis (RA) works differently. It's an autoimmune condition — the immune system mistakenly attacks the lining of the joints, driving inflammation that damages cartilage and bone over time. That inflammatory process is also why RA symptoms can flare and ease in cycles, and why RA more often comes with morning stiffness that lasts an hour or more.
Ankylosing spondylitis (AS), a related inflammatory condition, primarily affects the spine and sacroiliac joints, causing chronic back pain and stiffness that classically improves with movement and worsens with rest.
Despite the different mechanisms, the day-to-day experience overlaps heavily: reduced blood flow to the joint, muscle guarding around the painful area, and stiffness that's often worst first thing in the morning or after sitting still. That overlap is part of why heat-based therapies — which work primarily by improving local circulation and relaxing the muscles around a joint — show up as a supportive option across multiple types of arthritis, according to Mass General Brigham.
What the Research on Infrared Therapy Actually Shows
Two specific studies are worth understanding in some detail, because they're the ones most often cited — and most often oversimplified — in this space.
Infrared Sauna in Rheumatoid Arthritis and Ankylosing Spondylitis
A pilot study published in Clinical Rheumatology enrolled 36 patients — 18 with rheumatoid arthritis and 18 with ankylosing spondylitis — and had them complete eight infrared sauna sessions over four weeks (twice weekly, 30 minutes at 55°C). Researchers measured pain and stiffness before, during, and after the treatment period, plus a follow-up four weeks later.
The results were notable on two fronts. First, tolerance was good — sauna use didn't provoke disease flares. Second, pain and stiffness both dropped in a statistically significant way during individual sessions, with pain easing by roughly 40–60% and stiffness by roughly 50–60% across the two groups. The catch: those short-term gains faded somewhat during the longer follow-up period, though researchers noted “a trend towards long-term beneficial effects” rather than a clear, sustained result (PubMed).
In plain terms: infrared sauna produced real, measurable relief in the moment and shortly after, in a small study. Whether that translates into lasting improvement with regular long-term use is the open question — and exactly what a larger follow-up trial would need to confirm.
Infrared-A Irradiation in Osteoarthritis, Low Back Pain, and Rheumatoid Arthritis
A larger study, published in Acta Biochimica Polonica, took a different approach: 207 patients with degenerative osteoarthritis of the hip or knee, chronic low back pain, or rheumatoid arthritis were split into three groups — one receiving genuine infrared-A irradiation, one receiving a visible-light placebo, and one receiving no irradiation at all — over two weeks of treatment.
Across the treated groups, researchers documented meaningful pain reduction (measured on a standard visual analogue scale) and improved mobility, with the most pronounced effect in the low back pain group and clear, if more modest, gains in the osteoarthritis and rheumatoid arthritis groups. The study also checked a marker of oxidative stress (MDA) to see whether the infrared exposure was generating harmful free radicals — it wasn't; levels held steady or improved, which is a useful safety data point (PubMed).
Where the Broader Evidence Base Stands
Zooming out, a 2024 systematic review of infrared radiation for musculoskeletal conditions and chronic pain looked across 13 studies and found a genuinely mixed picture for osteoarthritis specifically: one trial of far-infrared plasters showed a meaningful improvement over several weeks, while two other knee osteoarthritis studies found no significant effect. The review's authors concluded that infrared therapy “appears as a safe and effective complementary therapy for a number of musculoskeletal conditions,” while cautioning that efficacy “remains debatable” for some conditions and that study sizes and follow-up periods are still too limited to settle the question (MDPI — Diagnostics).
That's a fair summary of where this category sits: consistent short-term relief in multiple small trials, a good safety profile, and a genuine need for larger, longer studies before anyone can call the case closed. None of this makes infrared therapy a treatment for arthritis itself — it's a complementary tool, not a substitute for the disease-modifying medications RA and AS often require.
How Each Product Can Support an Arthritis Routine
Infrared Sauna — for whole-body warmth on stiff, achy days
An infrared sauna is the closest at-home equivalent to the sessions used in the pilot study above — full-body heat that drives circulation and can ease both pain and stiffness in the short term, particularly useful before movement or on days when joints feel tight.
Key things to know:
• Sessions in the research were brief — around 30 minutes — so there's no need for marathon sessions to see the studied effect.
• Consistency (multiple sessions per week) tracks with where the research shows the clearest short-term benefit.
• If you're managing an active flare, check with your rheumatologist before sauna use — the pilot study population was in a relatively stable disease state, not mid-flare.
Infrared Mat — for a daily, low-effort dose of heat
An infrared mat brings the same infrared-A wavelengths studied above into a format you can use lying down, at home, without setup time — a practical option for the kind of frequent, brief sessions the research on osteoarthritis and low back pain used.
Key things to know:
• Because it requires no undressing or scheduling around a sauna, it's often the easiest way to build a consistent daily habit.
• Popular for targeted use over the low back, hips, or knees — the same joints highlighted in the research above.
• A reasonable starting point if you want to try infrared therapy before committing to a full sauna setup.
Red Light Therapy Couch — for full-body, hands-off relief
A red light therapy couch works through a related but distinct mechanism — photobiomodulation rather than heat — and is worth considering alongside infrared heat rather than instead of it. Research reviews describe its role in reducing inflammatory markers and modulating pain signaling, mechanisms that overlap with what arthritis patients are looking to address (PubMed — Mechanisms and Applications of the Anti-Inflammatory Effects of Photobiomodulation).
Key things to know:
• Sessions are short (10–20 minutes) and passive — helpful for days when even a warm sauna feels like too much.
• Because it covers large areas at once, it's a practical option for people managing pain in more than one joint.
• Many people pair red light sessions on non-sauna days as a complementary, lower-intensity option.
Frequently Asked Questions
Is infrared therapy a treatment for arthritis?
No. Infrared sauna, infrared mats, and red light therapy are not medical treatments and aren't a substitute for the disease-modifying medications, physical therapy, or specialist care that arthritis — especially rheumatoid arthritis and ankylosing spondylitis — often requires. The research above shows a supportive role in easing pain and stiffness, not disease reversal.
How much relief should I actually expect?
Based on the studies above, expect meaningful but short-term relief — pain and stiffness reductions during and shortly after sessions, most clearly demonstrated over two to four weeks of regular use. Whether that benefit holds up over months of ongoing use is still an open question the research hasn't fully answered.
Is infrared therapy safe to use during an arthritis flare?
This is worth asking your doctor directly. The infrared sauna pilot study was conducted in patients with relatively stable disease, and heat can sometimes aggravate an already-swollen, actively inflamed joint. The Mass General Brigham guidance on heat therapy specifically cautions against applying heat to joints that are swollen or already warm to the touch.
What's the difference between infrared heat and red light therapy for arthritis?
Infrared heat (saunas, mats) works primarily by warming tissue and increasing local circulation. Red light therapy uses specific light wavelengths to interact with cells at a different level, with research pointing to anti-inflammatory and pain-modulating effects. They're not competing options — many people use both for different reasons and at different times.
How often do the studies suggest using infrared therapy?
The sauna study used two sessions a week for four weeks; the infrared-A study used treatment over two weeks, generally more frequently. Neither establishes one “correct” long-term protocol — most people settle into a rhythm based on how their joints respond and what a doctor or physical therapist recommends.
Who should check with a doctor before starting?
Anyone with an active arthritis flare, uncontrolled cardiovascular disease, or who is pregnant should talk to their doctor before starting infrared sauna use. The same goes for anyone on medication that affects heat regulation or photosensitivity before starting red light therapy.
A Grounded Next Step
The research on infrared therapy and arthritis is a good example of science that's promising without being finished. Multiple independent studies point in the same direction — measurable short-term relief in pain and stiffness, a solid safety profile, and no evidence of harm — while also being honest that the long-term picture, and results in every type of arthritis, aren't settled yet.
If you're managing arthritis and thinking about where infrared therapy might fit into your routine, we're happy to help you think through which option — sauna, mat, or red light — matches your joints, your space, and how your body responds to heat.
This article is for general educational purposes and is not a substitute for professional medical advice. Infrared therapy is a complementary wellness practice, not a treatment for arthritis. Please consult your physician or rheumatologist before starting any new therapy, especially if you have an active flare, a cardiovascular condition, or are managing a chronic autoimmune disease.
Further Reading & Sources
• Mayo Clinic — Osteoarthritis: Symptoms and Causes
• Cleveland Clinic — Arthritis: Symptoms, Causes, Types, Treatment & Prevention
• Mass General Brigham — Arthritis Pain Relief: Ice or Heat?
• PubMed — Mechanisms and Applications of the Anti-Inflammatory Effects of Photobiomodulation
