Short answer: warmth often feels good on stiff, achy joints, and some people find a short infrared sauna session relaxing. But an infrared sauna is not a treatment for arthritis or any other joint condition, and the research is small. If joint pain is persistent, see a doctor; use a sauna only as a comfort measure alongside the care they recommend.
This article is general information, not medical advice.
What Heat Does to Your Body
In a sauna your body works to cool itself. Harvard Health notes that your pulse can rise by 30% or more, most of the extra blood flow goes to the skin, and you sweat. Infrared saunas warm you with infrared heaters at lower air temperatures than a traditional sauna, usually around 120°F to 140°F, but the cooling response is similar.
Warm muscles often feel looser, and many people simply feel more relaxed afterwards. That can make stiff joints feel easier to move for a while. It is a comfort effect, not proof that the sauna changes the condition behind the pain.
What the Research Shows
Small studies only: a 2009 pilot study in Clinical Rheumatology (Oosterveld et al.) gave 17 people with rheumatoid arthritis and 17 with ankylosing spondylitis eight infrared sauna sessions over four weeks. Pain and stiffness dropped during each session, and nobody had a flare or side effects. Over the four weeks, improvements were not statistically significant, and there was no comparison group. A study this small and short cannot show that saunas treat these conditions.
No replacement for treatment: nothing here suggests a sauna can replace medicines, physical therapy or the advice of your care team.
Individual results vary: some people with joint pain find heat soothing; others find it makes them feel worse, especially during a flare.
For a closer look at one condition, see our guide to infrared sauna and arthritis, and for the wider picture of what sauna research does and doesn't support, read infrared sauna benefits.
Heat or Cold? A Quick Guide
The Arthritis Foundation suggests heat for stiffness and cold for fresh swelling. A sauna is whole-body heat, so the same logic applies.
| Your joint feels | Better choice | Sauna? |
|---|---|---|
| Stiff and achy, no swelling (for example on waking) | Warmth | A short, moderate session may feel good |
| Suddenly swollen, red or hot after overdoing it | Cold for a few days | Skip it |
| In an arthritis flare | Follow your care team's plan | Skip it |
| Recently injured (sprain, fall) | Cold and rest at first; get it checked | Skip it until a clinician says heat is fine |
Joint Pain After a Workout
Sore muscles after exercise are a different problem from a joint condition. Some people like a warm session after training, and our guide on sauna before or after a workout covers timing and hydration. Rest, gentle movement and stretching are the usual first steps for everyday soreness.
When to Skip the Sauna
A joint that is red, hot, swollen or newly painful. Heat may not help, so get it checked first.
A recent injury. Ask a clinician before applying heat.
Fever or infection.
Any numbness in the area, since you may not feel a burn. Our nerve pain guide explains why.
Heart disease, uncontrolled high blood pressure, low blood pressure, pregnancy, or medicines that affect fluid balance or sweating: check with your doctor first.
How to Use an Infrared Sauna Safely
Keep sessions short: Harvard Health advises no more than 15 to 20 minutes. Start with about 10 minutes if you are new.
Start at a lower temperature and see how your joints feel afterwards. If they feel worse, stop.
Hydrate: drink water before and after, and cool down gradually.
Skip alcohol before and after a session.
Leave at once if you feel dizzy, light-headed or sick.
Our session time guide and first-timer's guide cover the basics.
When to See a Doctor
See a doctor for joint pain that lasts more than a few weeks, keeps coming back, wakes you at night, or comes with swelling, redness, warmth or fever. Get urgent care for a joint that suddenly cannot bear weight or for pain after a fall or injury.
The Bottom Line
An infrared sauna can be a warm, relaxing part of your routine, and some people with sore joints enjoy it. It is not a joint treatment, so keep your doctor involved and listen to your body.
