Are Hot Springs Good for You? What the Evidence Says

Are hot springs good for you? Two things are true at the same time, and a page that only tells you one of them is not answering the question.

The first: there is a real, formal evidence base. Bathing in thermal mineral water has a clinical name, balneotherapy, and it has been studied through systematic reviews conducted under the PRISMA Statement and registered on PROSPERO. One such review, published in the International Journal of Biometeorology in 2024, looked at thermal mineral water baths for skin disease and reported "a clear improvement of signs and symptoms of psoriasis and eczematous diseases" across every one of the eight studies it included.

The second: the same field's own methodologists say that evidence cannot yet carry much weight. A 2025 scoping review in BMC Complementary Medicine and Therapies examined 109 balneology trials published between 1990 and February 2025 and found that 74% sit in categories that completely lack blinding, only 11% used a double-blind design, and "over time, there has been no clear improvement in study design." Its conclusion, in its own words: "the ability to draw reliable conclusions about the true efficacy of balneotherapy remains limited."

The Short Answer, in Two Halves

The honest answer to "are hot springs good for you" has to hold both halves with equal weight, so here they are side by side.

Half one. The 2024 systematic review of thermal mineral water baths in dermatology was "conducted according to the PRISMA Statement, and its protocol was registered on PROSPERO platform (CRD42022295913)." That protocol was registered prospectively. Eight studies met the criteria. Every one of the eight reported a clear improvement in signs and symptoms of psoriasis and eczematous disease after thermal mineral water baths.

Half two. The 2025 scoping review on blinding in balneology trials opens by stating the standard the field is measured against: "In evidence-based medicine, randomized, placebo-controlled, double-blind clinical trials are considered the 'gold standard' of study design." Against that standard, 74% of the 109 trials it examined fall in the low categories that completely lack blinding, and only 11% were double-blind. The review's conclusion is that without improvements in design, "the ability to draw reliable conclusions about the true efficacy of balneotherapy remains limited."

Neither half cancels the other. The dermatology review is a real result that stands. The blinding review is a real limitation that also stands. The gap between them is where the actual answer lives: the evidence supports a specific statement about psoriasis and eczematous disease, and the sources cited here do not establish that hot springs are good for people at large.

What Balneotherapy Means

The 2024 review defines the field this way: "Balneotherapy includes practices and methods using medically and legally recognized mineral-medicinal waters, muds and natural gases from natural springs for therapeutic purposes."

Three parts of that definition matter for anyone reading a hot-springs health claim.

First, it is about mineral-medicinal water from natural springs, so it does cover the kind of water a hot spring produces. If you want the geology behind that water, the guide to how hot springs form and why they are hot covers where the heat comes from, and the article on the geothermal gradient explains why water gets hotter the deeper it circulates.

Second, the definition says "medically and legally recognized." The clinical field does not treat every warm pool in the ground as a treatment site; it works with waters that have been recognized as mineral-medicinal in a medical and legal sense. The sources cited here do not establish which hot springs anywhere meet that description, or what the recognition process involves. So a study of balneotherapy is a study of recognized mineral-medicinal water used therapeutically, which is not automatically the same as a study of the hot spring you are planning to visit.

Third, the definition says "for therapeutic purposes." Balneotherapy, as defined, is a treatment applied to a condition. So the evidence you should expect is trials of a treatment for a condition, not trials of whether bathing improves the health of people who have nothing wrong with them. That is exactly what the evidence turns out to be.

The Evidence That Exists: Eight Studies on Skin

The 2024 review in the International Journal of Biometeorology is the positive evidence in this article, so it deserves to be described precisely.

It is a systematic review. Its protocol was registered on PROSPERO under the identifier CRD42022295913, and the review was "conducted according to the PRISMA Statement."

The review included eight studies: "Eight studies were included, seven of them enrolled adults affected by psoriasis and one studied atopic dermatitis patients."

What those eight studies showed: "The common result of all the articles included was a clear improvement of signs and symptoms of psoriasis and eczematous diseases after use of thermal mineral water baths."

All eight included studies reported improvement. For a person with psoriasis, or with the atopic dermatitis studied in the eighth study, it is a real reason to raise thermal mineral water baths with their clinician.

It is also exactly as narrow as it sounds. The evidence comprises eight studies: seven on adults with psoriasis and one on atopic dermatitis. The extracted material says nothing about sleep, energy, stress, pain, joints, or how a healthy person feels after a soak, because that is not what the review covered. The sources cited here also do not establish how long the bathing courses ran, how hot the water was, or how frequently patients bathed, so this article gives no dose, duration, temperature, or frequency.

From Eight Psoriasis Trials to "Good for You"

The question "are hot springs good for you" is a general-population question. It asks whether soaking in a hot spring benefits a person, full stop. The evidence in the 2024 review is a condition-specific answer about psoriasis and eczematous disease in the patients studied. That condition-specific evidence does not answer the broader population-level question.

Here is what the jump from one to the other would require, and why the cited sources do not make it.

From patients to everyone. The eight studies enrolled people with a diagnosed skin condition. An improvement in the signs and symptoms of a disease is measured against that disease. There is no equivalent measurement for someone who does not have it. The sources cited here do not establish any benefit for people without psoriasis or eczematous disease.

From one system to the whole body. The dermatology review is about skin. Skin is where thermal water makes contact, and psoriasis and eczema are visible conditions where signs and symptoms can be scored. Nothing in the extracted material carries that finding to any other organ, system, or outcome. Osteoarthritis findings exist in the wider balneotherapy literature, but they were not extracted for this article, so no quote and no numbers for them appear here and this article does not cite them.

From clinical water to any hot spring. The review covers "medically and legally recognized mineral-medicinal waters." The sources cited here do not establish that a given hot spring, resort pool, or roadside soak meets that definition, and they do not establish what happens in water that does not.

From improvement to why. All eight studies found improvement. None of the extracted material says what caused it. That is not a gap in the review's reporting; it is the gap the next section is about, and the 2025 blinding review is what the next section is built on.

It is easy to step across that gap in a single sentence: a study found benefit for psoriasis, therefore hot springs have health benefits. A psoriasis finding cannot by itself support a general claim that hot springs are good for people. The eight studies do not say that, the review does not say that, and the field's own methodologists have explained why even the psoriasis result needs to be read carefully.

Why Blinding Is the Whole Problem

The 2025 scoping review in BMC Complementary Medicine and Therapies is titled "Challenges of blinding in clinical balneology trials," and the review identifies blinding as balneology's central methodological problem.

Start with the standard it invokes: "In evidence-based medicine, randomized, placebo-controlled, double-blind clinical trials are considered the 'gold standard' of study design." Randomized means patients are assigned to treatment or comparison by chance. Placebo-controlled means the comparison group gets something that looks and feels like the treatment but lacks the ingredient being tested. Double-blind means neither the patient nor the person assessing them knows who got which.

Now try to apply that to a hot spring. You cannot blind a person to whether they are sitting in warm water. And the things that come bundled with a thermal bath are not nothing: warm water on the body, rest, time away from routine, and a trip somewhere pleasant to get to the spring. Each of those could plausibly move how a person feels and how their symptoms are scored. A blinded, placebo-controlled trial is the tool that separates the specific effect of the mineral water from all of that, and it is the tool that is hardest to build for a treatment you experience with your whole body.

That is why the question of what the water itself does remains open. The sources cited here do not separate the effect of the minerals from the effect of warm water, rest, or being on holiday. The dermatology review reports that thermal mineral water baths were followed by improvement. It does not, in the material extracted here, tell you whether plain warm water would have done the same, because that is precisely the comparison blinding exists to make.

None of this is a criticism of balneotherapy from outside. The 2025 review is written by balneology researchers arguing for better balneology. Its authors want the field to produce trials that can survive the scrutiny applied to any other treatment. Their argument is for stronger trials within balneology.

109 Trials, 35 Years, No Clear Improvement

The 2025 review searched "Medline, Embase and Cochrane databases for trials published in any language between 1990 and 12 February 2025." It included 109 trials, then sorted them into categories according to how blinding was handled.

The numbers, in the review's own words:

"Low-category papers constituted the largest group, accounting for 74% of the total number of publications. From 1990 to the present, only 11% of publications chose the double-blind setup."

"Studies in the lower categories (1, 2, 3) completely lack blinding."

The review's results section gives that figure to two decimal places and names the categories: "low-category publications constitute the largest group, with categories 1, 2, and 3 together accounting for 74.31% of the total."

So roughly three in four balneology trials over the period sat in categories the review describes as lacking blinding, and about one in nine used the double-blind design it identifies as the gold standard. The review does not report that the remaining trials were all blinded, and this article does not claim it.

The finding that carries the heaviest weight is about the trend, or the lack of one: "Over time, there has been no clear improvement in study design." The search window runs from 1990 to 2025 — thirty-five years.

And the conclusion the authors draw from their own data: "Without these improvements, the ability to draw reliable conclusions about the true efficacy of balneotherapy remains limited."

Read that sentence next to the dermatology result and the shape of the honest answer is clear. Eight studies on psoriasis and eczematous disease all pointed toward improvement. The field's own methodologists, reviewing 109 trials, say balneology trial design does not yet allow reliable conclusions about true efficacy. The extracted material does not say which blinding category the eight dermatology studies fell into, so this article does not claim they were blinded and does not claim they were not. Together, the two sources establish a consistent positive signal sitting inside a literature whose own reviewers say it cannot yet be read with confidence.

How to Read a Hot Springs Health Claim

Thermal water is used at every scale, from a single spring to Iceland's national-scale geothermal systems, and its direct uses for heat are a separate subject. Health claims are their own category, and the two sources here give you five questions to ask of any page, brochure, or sign that makes one.

1. What condition is being claimed? The formal evidence cited here is about psoriasis and eczematous disease. A claim that names a specific condition can be checked against a specific study. A claim about health in general cannot be checked against anything in these sources, because the sources cited here do not establish a general-population benefit.

2. How big is the evidence, and on whom? The dermatology review rests on eight studies, seven on psoriasis in adults and one on atopic dermatitis. A page that turns numbers that small into a broad statement has added something the review did not.

3. Was the comparison blinded? By the 2025 review's count, 74% of balneology trials fall in categories with no blinding at all and 11% were double-blind. If a claim rests on a trial, the odds that the trial could separate the mineral water from warm water and rest are, on those figures, not high. A claim that omits the trial's blinding method leaves out a crucial limitation.

4. Does the water meet the definition? Balneotherapy uses "medically and legally recognized mineral-medicinal waters." The sources cited here do not establish which springs qualify. A study of recognized medicinal water is not a study of every hot spring.

5. Does the claim give a dose? The sources cited here give no duration, temperature, or frequency recommendation. Any page that does has taken it from somewhere else, and you should be able to see where.

This article is not medical advice, and a reader with psoriasis, eczema, or any other condition should talk to a clinician before treating a hot spring as a treatment.

What We Could Not Source

These are common hot-spring claims. The cited sources publish none of them, so this article makes none of them.

• The cited sources publish no finding on removing toxins, on any effect on the immune system, on metabolism, or on circulation. Those claims are absent from both reviews as extracted here, and they are absent from this article.
• The sources cited here do not establish any wellness benefit for people who do not have a diagnosed condition. The positive evidence is condition-specific: psoriasis and eczematous disease.
• The sources cited here do not establish any finding on joint conditions. Osteoarthritis appears in the wider balneotherapy literature but was not extracted for this article, so no result for it is cited.
• The sources cited here do not separate the effect of the minerals in the water from the effect of warm water, rest, or travel. The 2025 blinding review identifies the study designs that would make that separation as the ones the field lacks.
• The cited sources publish no dose, duration, temperature, or frequency recommendation, and this article gives none.
• The sources cited here do not establish which blinding category the eight dermatology studies belong to.
• The sources cited here do not establish which hot springs, if any, meet the "medically and legally recognized" definition used in the field.
• The sources cited here do not establish anything about the risks or safety of hot spring bathing, for any group. That silence is a limit of this article's sources, not a statement that no risks exist — our separate guide to whether hot springs are safe covers that question against its own sources.
• No commercial spa or resort is named here, because none is named in the sources.

Frequently Asked Questions

Is there any real scientific evidence that hot springs help with anything?

Yes, for specific skin conditions. A 2024 systematic review conducted under the PRISMA Statement and registered on PROSPERO (CRD42022295913) included eight studies of thermal mineral water baths, seven in adults with psoriasis and one in atopic dermatitis patients, and reported "a clear improvement of signs and symptoms of psoriasis and eczematous diseases" across all of them. That is the extent of the positive evidence in the sources cited here.

Why do researchers say the hot springs evidence is limited?

Because of blinding. A 2025 scoping review of 109 balneology trials published between 1990 and February 2025 found that 74% fall in categories that completely lack blinding, only 11% used a double-blind design, and "over time, there has been no clear improvement in study design." Without blinding, a trial cannot separate what the mineral water does from what warm water, rest, and a change of scene do. The review concludes that "the ability to draw reliable conclusions about the true efficacy of balneotherapy remains limited."

Is a hot spring the same thing as balneotherapy?

Not automatically. Balneotherapy, as defined in the 2024 review, uses "medically and legally recognized mineral-medicinal waters, muds and natural gases from natural springs for therapeutic purposes." The sources cited here do not establish which hot springs meet that definition. A trial of recognized mineral-medicinal water is not a trial of every warm pool in the ground.