Sauna and Peripheral Artery Disease: What the Research Shows
Key insights
- Peripheral artery disease (PAD) narrows the arteries to the legs, and the first-line treatment is supervised walking exercise, which many patients struggle to do because walking itself causes pain.
- Early Japanese work on Waon therapy (a gentle, low-temperature far-infrared sauna followed by blanket rest) reported better leg perfusion measures and symptoms in PAD patients, but those studies were small and uncontrolled.
- The most rigorous recent test, an 8-week sham-controlled trial of home leg heating, found a median 6-minute walk gain of 21.3 m versus roughly zero (−0.9 m) with sham, while most secondary outcomes did not differ.
- Heat is thought to work by dilating blood vessels, improving endothelial function and possibly stimulating new vessel growth, rather than by treating the underlying plaque.
- Heat therapy is, at best, a candidate adjunct to exercise and medical care for PAD, and anyone with PAD, ulcers or reduced sensation should clear it with their vascular clinician first.
Peripheral artery disease affects the arteries that supply the legs. As plaque narrows them, muscles receive too little blood during activity, producing the cramping calf pain known as intermittent claudication. The standard advice is structured walking, which works, but it is also the very thing that hurts. That tension is why researchers have asked whether warming the body or the legs might improve circulation without requiring exertion.
The idea is physiologically plausible. Heat opens blood vessels, increases skin and muscle blood flow and, with repeated exposure, appears to improve how the vessel lining behaves. Whether those changes translate into walking further with less pain is a separate question, and it is where the evidence becomes more modest than the headlines tend to suggest.
This article reviews what the published research shows. It is background for a conversation with a vascular clinician, not a treatment plan.
Why heat might help a narrowed artery
Warming the body triggers vasodilation, which lowers vascular resistance and raises blood flow through the skin and limbs. Repeated heat exposure is also linked to better endothelial function, the ability of the vessel lining to release nitric oxide and relax the vessel. A pooled analysis of heat-therapy trials examined effects on blood pressure and peripheral vascular function across studies, which is the kind of evidence that underpins this mechanism 5.
A second proposed pathway is angiogenesis, the growth of new small vessels around a blockage. Japanese researchers reported that Waon therapy mobilises CD34-positive cells, a population of circulating progenitor cells associated with vessel repair, in people with PAD 2. This is an intriguing signal, but cell counts are a mechanism marker, not a clinical outcome like walking distance.
What the early Waon studies reported
Waon therapy is a Japanese protocol using a far-infrared dry sauna at a comparatively low temperature (around 60°C), followed by a period of rest wrapped in a blanket to keep the body warm. In a 2007 report in the Journal of the American College of Cardiology, Tei and colleagues described Waon therapy improving PAD, including leg perfusion measures and symptoms 1. A follow-up study found the same therapy mobilised CD34-positive cells alongside clinical improvement 2.
These studies are historically important because they opened the field, but they were small and lacked sham-controlled comparison groups. Without a control arm it is impossible to separate the effect of heat from the effect of attention, expectation and ordinary fluctuation in claudication symptoms.
What the more rigorous trials show
A 2021 systematic review in Vascular Medicine specifically examined heat therapy for intermittent claudication due to PAD, and its authors treated the field as promising but early, with a small number of trials and methodological limitations 3.
The clearest single dataset comes from a pilot randomised trial of home-based leg heat therapy using water-circulating trousers. Over 8 weeks, the heat group (43°C) improved their 6-minute walk distance by a median of 21.3 m, compared with a median change of −0.9 m in the sham group (33°C), a statistically significant difference (P = 0.029). However, there were no significant differences in claudication onset time, peak walking time, oxygen consumption, ankle-brachial index or microvascular reactivity. Adherence was high (96%) and adverse events were minimal 4.
The honest reading is that heat therapy produced a modest, possibly meaningful improvement on one walking test in a small pilot, without clear changes in the vascular measurements that would explain it. That is encouraging for feasibility and safety, and insufficient to conclude it is an established treatment.
Realistic expectations
Heat does not remove plaque or reopen a blocked artery. Even in the most favourable studies, effects on walking were modest, and none of this evidence shows that sauna bathing reduces amputations, heart attacks or strokes in people with PAD. Supervised exercise, smoking cessation, blood-pressure and lipid control, and antiplatelet therapy remain the foundation of care.
There are also safety considerations specific to PAD. Reduced sensation, which is common when PAD coexists with diabetes, raises the risk of unnoticed burns. Open leg ulcers, severe limb ischaemia and unstable cardiovascular disease are situations where heat should not be self-prescribed. For broader context on how sauna affects the vessels, see our article on sauna and arterial stiffness.
Practical guidance
If your clinician agrees that heat is reasonable, the research points toward gentle, consistent exposure rather than intensity: moderate temperatures, shorter sessions, a gradual cool-down and attention to hydration. The sham-controlled trial used 43°C for the legs, well below a typical Finnish sauna. Treat heat as something that may sit alongside a walking programme, not replace it.
The Contrast Market Perspective
The PAD literature is a useful reminder that in heat therapy, dose and precision matter: the studies that worked used controlled, moderate temperatures, repeated reliably over weeks. That is an argument for equipment that holds its temperature accurately and behaves consistently session after session. If you are weighing a sauna for a specific health context, we are happy to talk it through. Schedule a consultation.
References
Footnotes
- Tei C, Shinsato T, Miyata M, Kihara T, Hamasaki S (2007). Waon therapy improves peripheral arterial disease. Journal of the American College of Cardiology. PubMed ↩︎
- Shinsato T, Miyata M, Kubozono T, Ikeda Y, Fujita S, Kuwahata S, Akasaki Y, Hamasaki S, Fujiwara H, Tei C (2010). Waon therapy mobilizes CD34+ cells and improves peripheral arterial disease. Journal of Cardiology. PubMed ↩︎
- Harwood AE, Pugh CJ, Steward CJ, Menzies C, Thake CD, Cullen T (2021). A systematic review of the role of heat therapy for patients with intermittent claudication due to peripheral artery disease. Vascular Medicine. PubMed ↩︎
- Monroe JC et al. (2022). Effects of home-based leg heat therapy on walking performance in patients with symptomatic peripheral artery disease: a pilot randomized trial. Journal of Applied Physiology. PubMed ↩︎
- Pizzey FK, Smith EC, Ruediger SL, Keating SE, Askew CD, Coombes JS, Bailey TG (2021). The effect of heat therapy on blood pressure and peripheral vascular function: a systematic review and meta-analysis. Experimental Physiology. PubMed ↩︎