Balneotherapy

Hydrotherapy in the Greek and Roman world

A 2022 historical review of Greek thermal springs reports that therapeutic use of water is recorded in ancient Greece since at least 1000 BC, and that priests of Asclepius, the god of medicine in Greek religion, ran sanctuaries offering medical services in places with suitable climate. The authors describe Hippocrates of Kos (460 to 375 BC) as regarded as the father of scientific medicine and of hydrotherapy. This is the authors' account of how later writers view him and not a finding about the effect of the baths.

According to the same review, the significance of water for health was widely recognised in the Hellenistic period, Roman doctors developed hydrotherapy treatment, and hot baths continued into the early Byzantine period until the sixth century AD. In Greece the Ottoman period brought a dominant form of public bath, the hamam. The review covers Greece only, so it cannot be read as an account of Roman Britain, Egypt or other regions.

From spa towns to national health systems

A 2024 article by a French university author traces French thermalism from the Roman thermae through the Renaissance and describes social security reimbursement of thermal treatment courses after the Second World War as the step that created the modern medical practice. This is a single secondary account written for a general audience, and it does not cover other European countries.

The sources opened for this page do not document the history of Dead Sea climatotherapy, mud therapy, Central European spa medicine or the nineteenth-century development of spa towns, and no dates are given here for them. The 2005 review by Nasermoaddeli and Kagamimori surveyed trials published from 1966 to 2003, which marks the period in which clinical studies of baths can be traced in the databases it searched.

Balneotherapy, spa therapy and hydrotherapy

Reviews use balneotherapy and spa therapy as near synonyms for bathing in water as a health measure, and Cochrane also lists mineral baths. A fibromyalgia review separates hydrotherapy, which generally uses normal tap water, from balneotherapy, which uses thermal mineral water from natural springs and also natural gases such as carbon dioxide, iodine, sulphur and radon, peloids (therapeutic mud) and other earth-based remedies.

The Greek historical review defines thermal-mineral waters as hot waters above 20 degrees Celsius with total dissolved salts above 1 gram per litre, and lists inhalation, drinking and mud therapy alongside immersion under hydrotherapy. These are definitions used by those authors, and other countries and spa associations may set different thresholds.

One label, many interventions

Trials grouped under the label differ widely. The Cochrane osteoarthritis review included spa treatment against no treatment, baths added to home exercises, thermal water against tap water, and sulphur or Dead Sea baths. The Cochrane rheumatoid arthritis review covered mudpacks, radon in carbon dioxide baths and seated immersion against exercise in water. A separate Cochrane review of indoor artificial salt baths followed by ultraviolet B light for psoriasis simulates sea bathing and sunlight and is not the same as bathing at a natural spring.

What the trials delivered

In a review of nine randomised trials of natural thermal mineral water for knee osteoarthritis, trial duration ranged from 10 to 24 weeks with a median of about 15 weeks. The Cochrane rheumatoid arthritis review included nine studies with 579 participants. The psoriasis review included eight randomised trials, lasting from at least two months to 13 months, all set in Europe and mostly in Germany, in spa centres or outpatient clinics. These are research protocols and not descriptions of typical practice.

Prescribed thermal courses in France

The 2024 article describes French thermal courses as prescribed by health professionals for eligible conditions, with an on-site medical evaluation that determines the treatments given. A course typically lasts three weeks, with sessions each morning except Sundays, and the author says reimbursed courses cannot take place during sick leave. This describes one country as presented by one author. The sources reviewed give no verified account of how spa care is organised, paid for or supervised in Germany, Hungary, Italy or elsewhere.

Conditions named in reviews

Nasermoaddeli and Kagamimori described atopic dermatitis, psoriasis, rheumatoid arthritis, ankylosing spondylitis, osteoarthritis and low back pain as conditions frequently treated by balneotherapy with a remarkable rate of success, and suggested chemical, thermal and mechanical effects as probable mechanisms. That review included non-randomised trials and was published in 2005. Both the success claim and the proposed mechanisms are the authors' statements and should be read against the controlled trial findings below.

An overview of 18 systematic reviews with meta-analysis found that 44% concerned musculoskeletal or connective tissue diseases, 28% symptoms and signs, 22% circulatory diseases and 6% nervous system diseases, which shows where research has concentrated.

Traditional indications in French thermalism

The French article states that thermal waters are recognised for digestive, mucosal, urinary, dermatological, gynaecological, cardiovascular, neurological, psychosomatic, vein, rheumatological, developmental and respiratory disorders, with specific mineral compositions linked to particular uses. It also says thermal treatment reduces drug use. These are the author's statements about an established practice, and none of the controlled studies reviewed on this page tested them.

Osteoarthritis

The 2007 Cochrane review (searches to October 2006) included seven trials with 498 patients. It reported silver-level evidence of benefit from mineral baths against no treatment for pain, quality of life and analgesic intake, but Dead Sea plus sulphur baths differed from no treatment only at the end of treatment and not at three months, and Dead Sea baths alone or sulphur baths alone showed no significant difference. The reviewers judged the evidence weak because of poor methodology and said the positive findings should be viewed with caution.

A 2009 review of nine randomised trials (493 patients) of thermal mineral waters in knee osteoarthritis reported improved pain and function sustained to week 24 and no serious adverse events, and called for larger, longer trials.

Rheumatoid arthritis and spondyloarthritis

The Cochrane review on rheumatoid arthritis (nine studies, 579 participants, searches to December 2014) found mostly unclear risk of bias. Mudpacks against placebo showed no significant difference (one study, 45 people, very low-level evidence), and radon in carbon dioxide baths showed none at three months (two studies, 194 people) but some pain benefit at six months with moderate-level evidence. It concluded that evidence was insufficient to show balneotherapy is more effective than no treatment or another treatment.

A 2022 review of nine randomised trials in spondyloarthritis (searches to July 2017) found high internal validity in only two. Its authors stated that the review was not sufficient to prove efficacy and called for larger trials.

Back pain, fibromyalgia and psoriasis

A 2026 network meta-analysis of 26 trials in chronic non-specific low back pain reported lower pain with balneotherapy than blank control (standardised mean difference 1.27, 95% confidence interval 0.19 to 2.35), but heterogeneity exceeded 85% and the authors called the results preliminary. No Cochrane review of balneotherapy for low back pain was found in a PubMed search for this page.

A 2014 fibromyalgia review reported its pooled pain result for hydrotherapy, not balneotherapy. A 2020 Cochrane review found low-certainty evidence that salt baths plus ultraviolet B light may improve psoriasis against light alone (risk ratio 1.71 for 75% improvement, 278 people).

Quality of the trials

In the fibromyalgia review only 5 of 24 studies had low risk of bias, and balneotherapy studies were of lower quality than hydrotherapy studies. A 2009 summary of systematic reviews concluded that poor methodological quality prevented conclusions on balneotherapy, while a 2020 overview of 18 reviews by the same group reported significant pain relief and quality-of-life gains in chronic musculoskeletal disease. These readings of the same literature differ.

Funding and what remains untested

In the psoriasis review, commercial spa or salt companies sponsored three of eight trials, and the German Spas Association funded one of the two trials supplying the main result. Seven of the eight were at high risk of bias in at least one domain. The sources reviewed do not test Dead Sea climatotherapy as a whole programme, long-term outcomes, or comparisons with exercise in most conditions.

Adverse events in trials

Adverse events were not measured in the trials in the Cochrane osteoarthritis review. In the fibromyalgia review, four studies reported adverse events, none serious, seven stated there were none and thirteen gave no information. In the psoriasis review, one study reported skin irritation and one participant had severe itch after a Dead Sea salt soak. Poor reporting means the absence of reports does not show that no harm occurred.

Hygiene, suitability and training

The Greek historical review notes that Pseudomonas aeruginosa is commonly isolated from pool environments and that bathers shed about 100,000 to 1,000,000 colony-forming units each in 15 minutes. No source opened for this page gives a verified list of contraindications for people with heart disease, pregnancy or infection, so none is listed here. Nasermoaddeli and Kagamimori suggest balneotherapy be considered after or alongside orthodox treatment, and bathing should not delay or replace necessary medical care.

No professional body, register or training standard for spa practitioners was verified in the sources reviewed, and none is described here. The French article says thermal courses are prescribed by health professionals after an on-site medical evaluation, which describes one country only.