Thermal & cold
Steam Room (steam bath, hammam)
Graded on: any health outcome of regular steam room use, steam compared with no steam.
Grade D, not yet tested: no human randomized trial has been run. This D records missing trials, not a finding that it does not work. How to read a grade →
At a glance
A steam room is a warm room filled with steam, so the air is soaking wet but not as hot as a sauna. A Turkish hammam is a kind of steam room. No study has tested whether using a steam room regularly improves health compared with not using one. In one study, steam with herbs worked no better than plain steam for hay fever. Many people find wet heat harder to tolerate than dry heat.
A letter describes the human evidence, not the product, the manufacturer, or the intervention's worth.
See the full evidence record →No human randomized trial has tested this at the dose and form graded, so there is nothing for a higher letter to rest on. A Route 1 Grade D records the absence of trials. It is not a finding against the compound, and it is not a finding that the compound is safe, because neither has been established. It may turn out to work once someone tests it. The grade moves when a qualifying human trial reports.
Graded on Any health outcome of regular steam room use, steam compared with no steam.
Why this letter
Why this gradeGrade D, not yet tested. The reasoning, and what the grade does not cover.
Grade D on Route 1: untested. No randomized trial has compared regular steam room use with no steam room on any health outcome. The one trial in allergic rhinitis gave both groups steam and varied only the herbs, so it tells us the herbs added nothing, not whether steam helps (Tungsukruthai et al., 2018; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 29397091). The hammam trial in endometriosis pain combined steam with massage in the same sessions (Rodriguez-Ruiz et al., 2024; PMID 39459464).
WHAT THIS GRADE DOES NOT COVERbreathing steam from a bowl or inhaler for a cold or sinus symptoms, which has been tested and is graded on its own record; dry saunas, Finnish or infrared, which have their own records.
A grade describes the human evidence for a named use. It is not advice, and it is not a judgment on any individual prescription. How the letters are decided →
Evidence notes: no randomized trial
Endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score. graded: Any health outcome of regular steam room use, steam compared with no steam (surrogate)
Last reviewed: October 2026
The trial that would change this grade.
A positive trial of this shape would move this entry to C.
Why the current trials fall short
No trial has tested steam against no steam. Even one well-run trial would move this record off Route 1.
Why people believe itTwo human sources; no published case reports of benefit; one report of harm.
The case for the steam room borrows from the sauna: heat widens the blood vessels and raises the heart rate, and the steam is said to clear the airways and open the pores. Steam baths have a long history across many cultures, from the Turkish hammam to the Russian banya, and most of the health claims made for them are claims made for sauna in general.
What supporters point to, and what each source actually shows. None of it is enough to move this letter higher; the trial described above under Evidence wanted is what would.
- Human trial, blood or body markerIn 40 healthy adults, lung function measures were higher after 12 weekly steam bath sessions than before. A before-and-after comparison with no control group. PMID 33957713
- Human trial, blood or body markerIn 12 men, an hour in a portable steam pod at 44 degrees Celsius and 99 percent humidity raised rectal temperature to about 38.1 degrees Celsius and heart rate to about 124 beats a minute, reliably from one week to the next. A measurement of heat strain, not a health outcome. PMID 37979477
A case report describes what happened to one or a few patients. It cannot show the treatment caused the change, and reports of success are published more often than reports of failure.
A PubMed search in October 2026 found no published case report of benefit for this use.
- A 54-year-old man with knee arthritis developed a Mycobacterium abscessus joint infection after high-temperature herbal steam baths applied to the knee. PMID 40881680
Searched PubMed, October 2026: 7 case report record(s) returned. One describes harm tied to steam, listed. The rest mention a hammam or steam bath in passing (a skin metastasis, a parasitic infection, a contact lens infection, a heat rash) or concern a dry sauna.
Dose, form and timing
Nothing validated. Session temperature, humidity and minutes, if a steam room is used, so it can be compared with the conditions in the studies above (about 44 degrees Celsius and 99 percent humidity in the 2023 pod study).
Safety
In a crossover A trial design in which each participant receives both the treatment and the comparison, one after the other, and serves as their own control. study of 13 active adults, passive heat in humid air was tolerated less well than hot water immersion, and tolerance did not improve over 5 days (PMID 35193165). Wood-fired steam baths used in highland Guatemala exposed bathers to high levels of carbon monoxide (PMID 21618942). A 54-year-old man developed a Mycobacterium abscessus infection of the knee after repeated high-temperature herbal steam baths applied to the knee (PMID 40881680).
Grade history
How this letter has changedLatest: October 2026 · First graded.
Steam rooms, steam baths and Turkish hammams now have a record. No randomized trial has compared regular steam room use with no steam on a health outcome: a trial in allergic rhinitis gave both groups steam and varied only the herbs (Tungsukruthai et al., J Integr Med, 2018; PMID 29397091), and a hammam trial in endometriosis pain combined steam with massage (Rodriguez-Ruiz et al., Medicina, 2024; PMID 39459464). Grade D on Route 1.PMID 29397091 PMID 39459464
Every change to a letter on this site is dated and published. The full evidence log →
Sources
The evidence, in fullSix papers, each linked to its PubMed record.
Tungsukruthai et al. (J Integr Med, 2018; PMID 29397091): 64 adults with allergic rhinitis randomized to herbal steam or plain steam, 30 minutes three times a week for 4 weeks; symptoms fell in both groups, with no difference between them, and no group went without steam. Rodriguez-Ruiz et al. (Medicina, 2024; PMID 39459464): 44 women with endometriosis pain randomized to a 4-week hammam program combining hydrotherapy and Swedish massage, or usual care; menstrual pain and pain with intercourse improved, but the steam cannot be separated from the massage. Oberg et al. (J Cosmet Dermatol, 2019; PMID 30588730): hammam scrubbing did not increase sunburn. Pandiaraja et al. (J Complement Integr Med, 2022; PMID 33957713): lung function rose in 40 healthy adults after 12 weekly steam sessions, with no control group. Willmott et al. (J Therm Biol, 2023; PMID 37979477): a portable steam pod at 44 degrees Celsius and 99 percent humidity raised rectal temperature to about 38.1 degrees Celsius in an hour. Campbell et al. (Exp Physiol, 2022; PMID 35193165): passive heat in humid air was tolerated less well than hot water immersion. Grade D, Route 1.
Primary evidenceSix papers, each linked to its PubMed record.
Tungsukruthai et al. (J Integr Med, 2018; PMID 29397091): 64 adults with allergic rhinitis randomized to herbal steam or plain steam, 30 minutes three times a week for 4 weeks; symptoms fell in both groups, with no difference between them, and no group went without steam. Rodriguez-Ruiz et al. (Medicina, 2024; PMID 39459464): 44 women with endometriosis pain randomized to a 4-week hammam program combining hydrotherapy and Swedish massage, or usual care; menstrual pain and pain with intercourse improved, but the steam cannot be separated from the massage. Oberg et al. (J Cosmet Dermatol, 2019; PMID 30588730): hammam scrubbing did not increase sunburn. Pandiaraja et al. (J Complement Integr Med, 2022; PMID 33957713): lung function rose in 40 healthy adults after 12 weekly steam sessions, with no control group. Willmott et al. (J Therm Biol, 2023; PMID 37979477): a portable steam pod at 44 degrees Celsius and 99 percent humidity raised rectal temperature to about 38.1 degrees Celsius in an hour. Campbell et al. (Exp Physiol, 2022; PMID 35193165): passive heat in humid air was tolerated less well than hot water immersion. Grade D, Route 1.
Evidence Based Longevity, Inc. is owner-operated and edited by Arnold Sandlow, D.C., a California-licensed chiropractor. Evidence Based Longevity publishes in English only · Machine translations are not produced or reviewed by EBL for accuracy
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