Key Takeaway
A systematic review of 40 studies found that regular dry sauna bathing is generally well tolerated and associated with benefits for cardiovascular function, pain conditions, and overall well-being, with minimal adverse effects.
Summary
Hussain and Cohen conducted a systematic review of clinical evidence on the health effects of regular dry sauna bathing. They searched multiple databases and identified 40 studies meeting inclusion criteria, encompassing a range of study designs from randomized controlled trials to observational studies, covering diverse populations including those with cardiovascular disease, chronic pain, and healthy individuals.
The review found consistent evidence of cardiovascular benefits including improved vascular function, reduced blood pressure, and enhanced endothelial function. Studies in patients with chronic heart failure showed improvements in cardiac function, exercise tolerance, and quality of life. Beyond cardiovascular outcomes, regular sauna bathing was associated with reduced pain and improved function in conditions like rheumatic diseases and fibromyalgia, as well as improvements in headache disorders, common colds, and overall quality of life.
The authors noted that dry sauna bathing appears safe for most people, with adverse events being rare and generally mild (e.g., transient hypotension, heat discomfort). However, they highlighted that many studies had small sample sizes, short follow-up periods, and heterogeneous protocols, making it difficult to establish firm dose-response relationships or definitive clinical recommendations.
Methods
Systematic review following PRISMA guidelines. Searched PubMed, CINAHL, Cochrane Library, and Embase for clinical studies on dry sauna bathing. Included 40 studies of various designs (RCTs, crossover trials, cohort studies, case series) published through 2017. Assessed study quality and extracted data on health outcomes, adverse events, and sauna protocols.
Key Results
- Cardiovascular: Improved endothelial function, reduced arterial stiffness, lower blood pressure, and improved left ventricular function in heart failure patients.
- Pain: Reduced symptoms in rheumatic diseases, chronic musculoskeletal pain, fibromyalgia, and chronic headache.
- Respiratory: Reduced incidence and severity of common colds in regular sauna users.
- Well-being: Improved quality of life scores and relaxation across multiple studies.
- Safety: Adverse events were rare and mild; no serious adverse events reported in the included studies.
- Protocols varied widely: temperatures 80-100°C, durations 5-30 minutes, frequencies 1-7 sessions per week.
Limitations
- Many included studies had small sample sizes (often <50 participants).
- Heterogeneous sauna protocols make dose-response analysis difficult.
- Most studies were short-term (weeks to months), limiting conclusions about long-term effects.
- Risk of bias was moderate to high in several studies due to lack of blinding and randomization.
- Limited representation of women, younger adults, and non-European populations.
- Publication bias toward positive results is possible.