As far as I know, a possible therapy for rheumatism and arthritis can be "radon therapy". My understanding is that this means bathing in a tub with water that contains radon.

My question is, if this is

  1. a helpful therapy and if
  2. the occurring radiation is harmful.

Are the statements 1. and 2. true?

This is an article published by scientists affiliated with a therapy center. I couldn't find an English full text version, but there should be one somewhere from 2015.

  • Not too sure about the tags, feel free to edit.
    – Tom K.
    Commented Feb 9, 2018 at 16:43
  • Welcome to HealthSE, Tom K.! Please take the tour and read the help center. Just to be sure: Personalised medical advice is off-topic here. You may improve your question to comply with site guidelines with an edit and the help of How to Ask. Making it just slightly more general should remove doubts on that. Thanks! Commented Feb 9, 2018 at 16:54
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    Edited, I hope this meets the guidelines now. I'm not seeking personalised medical advice. I'm just interested in this form of therapy.
    – Tom K.
    Commented Feb 9, 2018 at 17:04

1 Answer 1


Terminology note: I am going on the assumption that by 'rheumatism' you are referring to rheumatoid arthritis, a chronic destructive inflammatory condition

There is not good or sufficient evidence to suggest that 'Radon bathing' confers symptomatic benefit for rheumatoid arthritis (and possibly some other diseases)

Is radon therapy a 'helpful therapy'?

This is a tricky-ish one to answer definitively. The best I can say is that I remain (healthily) skeptical of the evidence.

A 2012 study in mice (PDF) concluded "Radon therapy ameliorates the inflammatory processes responsible for the arthritogenic activity of human TNF in mice."; however, (1) that was in mice, not humans; and (2) the numbers involved were quite small (17 vs 18) and I cannot see any analysis to suggest their results are statistically significant.

The journal Dose-Response seems to have published a number of papers on the subject:

How might radon be helpful? From the first article:

The exact mechanism of radon's effect on human body is not completely understood. However, the most favored hypothesis is that radon's action is mediated by the neuroendocrine system, stimulation of the suprarenal glands by the hypophysis, rather than by direct action on the T cells.

The last one is a general discussion of the use low-dose ionising radiation (ie not limited to radon) to treat disease. Specifically to rheumatoid arthritis, it references a 2005 review and meta-analysis which conclude there is benefit, but should be treated with some skepticism as the author is affiliated with Gasteiner Heilstollen Hospital, which offers radon spa therapy.

It seems that there may be a potential benefit for low-dose ionising radiation via neuroendocrine induction; but the evidence is (at worst) anecdotal and not extensive.

Another study from 2015 indicates that benefit of radon spa treatment may be 'due to chance':

adding radon to carbon dioxide baths did not improve pain intensity at three months but may improve overall well-being and pain at six months compared with carbon dioxide baths without radon, but this may have happened by chance.

Note: That study includes an excellent 'plain language' summary.

As far as I am aware, radon therapy is not available via the NHS in the UK.

Overall, there is no high-quality level one data to support the use of radon therapy for rheumatoid arthritis*.

Radon exposure (due to gas build-up in homes) definitely is harmful

From the National Cancer Institute:

Radon is a radioactive gas released from the normal decay of the elements uranium, thorium, and radium in rocks and soil. It is an invisible, odorless, tasteless gas that seeps up through the ground and diffuses into the air.


Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon. There has been a suggestion of increased risk of leukemia associated with radon exposure in adults and children; however, the evidence is not conclusive.

So long term exposure to radon causes lung cancer, and is apparently the second-leading cause of lung cancer after smoking.

As such it is important to be aware of the risks of indoor radon exposure.

So is spa radon harmful?

Given the smaller doses involved, it is hard to answer given the paucity of evidence; but I didn't find any bold, obvious warnings or studies to suggest that.

From the 2015 article on balneotherapy referrer to earlier:

we do not have precise information about side effects and complications of balneotherapy. This is particularly true for rare side effects. Side effects may include skin rash, infection and accidents, for example, slipping on wet surfaces near the bath area. The only study that reported side effects stated that they did not find any.

So I would not go so far as to label it 'safe'.

*: Credit to Graham Chiu for suggesting this qualifier.


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    Most excellent. Commented Feb 9, 2018 at 20:08
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    I think you need to state that there is no high quality level one data to support the use of radon in rheumatoid arthritis. Commented Feb 10, 2018 at 17:43
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    @GrahamChiu Interesting suggestion; do you reckon that is clearer than "but there is not good or widespread evidence for this" in the tl;dr section at the start? I think they both amount to saying the same thing, but wanted to keep the initial section slightly more layman friendly as that's what they'll see first. I could add that as a concluding sentence perhaps? Happy to hear your thoughts
    – bertieb
    Commented Feb 10, 2018 at 18:27
  • Why have a summary that talks of potential but unproven benefit? It's best to steer patients away from at best placebo treatment. The data available is not going to meet any modern criteria for effectiveness. Commented Feb 11, 2018 at 0:30
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    Welcome back bertieb! Thank you for the great answer and wealth of research incorporated. You did a great job of editing it per GrahamChiu's suggestions, which I agree with. We're thrilled to have more medical professionals/students involved in the site! I look forward to having you into the voting ranks when your rep hits 1000.
    – DoctorWhom
    Commented Feb 11, 2018 at 11:37

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