Sauna for recurrent upper respiratory tract infections and pneumonia risk
Evidence review
Overview
A 1990 controlled trial reported about half as many common colds in the later months among volunteers taking regular saunas, with no difference in cold duration or severity, and a 1992 German study of 20 nursery-school children reported fewer respiratory infections and illness days over one year in those taking regular saunas. In the Finnish KIHD cohort, men who used the sauna 2 or more times per week had a lower rate of hospital-diagnosed pneumonia over about 25 years; in a later analysis the lowest risk was seen in men with both high fitness and frequent sauna use. Inhaling hot sauna air during an established cold did not reduce overall symptom severity in a randomized trial of 157 patients. The evidence concerns prevention in healthy adults and children rather than treatment in people with documented recurrent infections.
Key findings
- Significantly fewer common colds with regular sauna over 6 months, roughly halved in the last 3 months; no change in duration or severity (Ernst 1990, n=50)
- Fewer acute respiratory infections and days of illness over one year with regular sauna vs none; salivary IgA rose after sauna from 6 months (Conradi 1992, n=20 children, no figures in abstract)
- Hot sauna-air inhalation during an acute cold: symptom AUC difference -3.9 (95% CI -9.7 to 1.9), P=0.19 (Pach 2010, n=157)
- Pneumonia HR 0.69 (0.55-0.86) for 2-3 and 0.56 (0.35-0.88) for >=4 vs <=1 session/week (Kunutsor 2017, n=2,210)
- Pneumonia HR 0.81 (0.68-0.97) for 2-7 vs <=1 session/week; 0.62 (0.48-0.80) with high fitness plus frequent sauna (Kunutsor 2021, n=2,275, same cohort)
Every study we reviewed
5 found benefit · 1 found no effect
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 18 studies on respiratory infections, across all heat and cold therapies, including case reports and older work not graded here.
Regular sauna bathing and the incidence of common colds.
Ernst E et al. Ann Med. 1990. PubMed 2248758 · DOI
- Who
- healthy volunteers
- What
- regular sauna bathing vs abstaining from sauna or comparable procedures
- Protocol
- 26 wk
- Measured
- frequency, duration and severity of common colds
- Result
- Significantly fewer episodes of common cold in the sauna group, particularly in the last 3 months when incidence was roughly halved; mean duration and severity did not differ.
- Limitations
- small; allocation method not described in abstract; healthy volunteers rather than patients with recurrent infections; unblinded
Visiting a sauna: does inhaling hot dry air reduce common cold symptoms? A randomised controlled trial.
Pach D et al. Med J Aust. 2010. PubMed 21143077 · DOI · Free full text
- Who
- adults with a newly acquired common cold
- What
- inhaling hot dry sauna air vs room-temperature dry air, both inside a hot sauna wearing a winter coat
- Protocol
- daily/wk · 3 days
- Measured
- symptom severity AUC over 7 days
- Result
- AUC 31.2 vs 35.1, difference -3.9 (95% CI -9.7 to 1.9), P=0.19; secondary differences in day-1 medication use (P=0.01) and day-2 symptoms (P=0.04).
- Limitations
- tests treatment of an acute cold, not prevention; single blind
Frequent sauna bathing may reduce the risk of pneumonia in middle-aged Caucasian men: The KIHD prospective cohort study.
Kunutsor SK et al. Respir Med. 2017. PubMed 29229091 · DOI · Free full text
- Who
- Finnish men aged 42-61 (KIHD)
- What
- self-reported sauna frequency, 2-3 or >=4 vs <=1 session/week
- Protocol
- <=1 vs 2-3 vs >=4/wk
- Measured
- hospital-diagnosed pneumonia
- Result
- Multivariable HR 0.69 (95% CI 0.55-0.86) and 0.56 (0.35-0.88); after further adjustment 0.72 (0.57-0.90) and 0.63 (0.39-1.00). 375 cases over median 25.6 years.
- Limitations
- observational; men only; residual confounding possible
Attenuated Risk of Pneumonia Due to Inflammation by Frequent Sauna Baths: A PROSPECTIVE COHORT STUDY.
Kunutsor SK et al. J Cardiopulm Rehabil Prev. 2022. PubMed 33797457 · DOI · Free full text
- Who
- Finnish men aged 42-61 (KIHD)
- What
- high (2-7) vs low (<=1) sauna sessions/week, with hsCRP
- Protocol
- <=1 vs 2-7/wk
- Measured
- incident pneumonia
- Result
- High vs low sauna frequency HR 0.79 (95% CI 0.66-0.95); high hsCRP with low sauna frequency HR 1.67 (1.21-2.29) vs normal hsCRP and low frequency. 528 cases over median 26.6 years.
- Limitations
- same cohort as Kunutsor 2017; observational; men only
High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study: Are there potential implications for COVID-19?
Kunutsor SK et al. Eur J Clin Invest. 2021. PubMed 33426640 · DOI · Free full text
- Who
- Finnish men aged 42-61 (KIHD)
- What
- self-reported sauna frequency, high (2-7) vs low (<=1) sessions/week, jointly with measured cardiorespiratory fitness
- Protocol
- <=1 vs 2-7/wk
- Measured
- incident pneumonia
- Result
- High vs low sauna frequency HR 0.81 (95% CI 0.68-0.97); vs low fitness and low sauna, low fitness with high sauna HR 0.89 (0.71-1.13) and high fitness with high sauna HR 0.62 (0.48-0.80). 529 cases over median 26.6 years.
- Limitations
- same cohort as Kunutsor 2017 and 2022; observational; men only; COVID-19 not studied
Frequency of acute respiratory illness and salivary secretory immunoglobulin A under the influence of regular sauna bathing in children
Conradi E et al. Physikalische Medizin, Rehabilitationsmedizin, Kurortmedizin. 1992. Not in PubMed: source · DOIGerman publication; title and summary translated by SaunaLMN. Original title: Häufigkeit akuter respiratorischer Erkrankungen und sekretorisches Immunglobulin A im Speichel unter dem Einfluß regelmäßigen Saunabadens von Kindern
- Who
- Nursery-school children (11 taking regular saunas, 9 controls) (Germany)
- What
- Regular sauna bathing over one year (session details not given in the abstract) vs no sauna
- Protocol
- 52 wk
- Measured
- Number of acute respiratory infections and days of illness; salivary secretory IgA before and after sauna (6 times)
- Result
- The sauna group had significantly fewer infections and fewer days of illness than controls (figures not given in the abstract); after 6 months, each sauna session was followed by a significant rise in salivary IgA.
- Limitations
- 20 healthy children; allocation method not stated; no figures in the abstract; prevention in healthy children, not treatment of recurrent infections.
Protocols used in the studies
The prevention trials used regular sauna bathing for 6 months in adults or 1 year in nursery-school children (details not in abstracts). Cohort exposures were 2-3 or 4-7 traditional sauna sessions per week. The acute-cold trial used 3 days of sauna exposure.
What is still unknown
Randomized trials in people with recurrent respiratory infections; mechanism; generalizability to women and non-Finnish populations.
Safety
Cautions for sauna in this condition
- Sauna is not a treatment for acute febrile illness; heat exposure during fever adds thermal load.
- Legionella pneumonia linked to a sauna has been reported (case reports, PMID 16171106); this concerns water systems in communal facilities.
- See general-safety.
For clinicians
Suggested rationale
A controlled trial (Ernst 1990) found fewer common colds with regular sauna bathing, and in a 25-year Finnish cohort (Kunutsor 2017; Kunutsor 2021) 2 or more sauna sessions per week was associated with lower pneumonia risk; evidence in patients with documented recurrent infections is lacking.
Suggested wording only. The treating clinician decides whether it reflects their clinical judgment for this patient.
Typical ICD-10 codes: J06.9, J18.9, Z87.01. Examples only; the clinician assigns the code.
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