GradedHealth

Does sauna use help your heart and add years to your life?

Large Finnish studies link sauna use 4 or more times a week to fewer heart deaths and longer life. The catch: the evidence is observational.

Published October 2026

Short answer

Finnish cohort studies link sauna use 4 or more times a week to fewer heart deaths and strokes and to living longer, but the findings are observational, from one population — an encouraging link, not proof. Evidence grade C (Limited). Multiple large, consistent prospective cohorts, but from one Finnish study group and observational only; no randomised trial has measured deaths.

Key takeaways

  • In 2,315 Finnish men followed for about 21 years, using the sauna 4 to 7 times a week was linked to about a 60% lower risk of sudden cardiac death than going once a week [1].
  • In these cohorts, frequent sauna use was also linked to fewer fatal heart disease cases, strokes and dementia cases [2][3][4].
  • The longevity link is modest: 3 to 7 sauna sessions a week were linked to a 14% lower risk of death from any cause in 2,575 men [5].
  • It is all observational, from one Finnish population, so it shows frequent sauna users lived longer, not that the sauna caused it [1][4].
  • Use it sensibly: dizziness, fainting and slips cause most sauna injuries, and alcohol in the sauna has been involved in serious cases [6][7].

The short version

Large Finnish cohort studies link regular sauna use — four or more sessions a week — to fewer deaths from heart disease and stroke, and to a longer life [1][2][3][5]. But the evidence is observational and comes almost entirely from one population in eastern Finland, so it shows an association, not proof that the sauna itself is doing the work [4][5]. The randomised trials so far have measured markers like blood pressure, not deaths [8].

What the studies show

Almost everything we know about sauna and heart health comes from the Kuopio Ischaemic Heart Disease study, which has followed middle-aged men in eastern Finland since the 1980s [1]. In 2,315 of those men, followed for a median of about 21 years, using the sauna 4 to 7 times a week was linked to a 63% lower risk of sudden cardiac death than going once a week (hazard ratio 0.37); fatal heart disease, fatal cardiovascular disease and all-cause deaths followed similar patterns [1]. Sessions lasting more than 19 minutes were linked to a lower risk of sudden cardiac death than sessions under 11 minutes [1].

Studies that included women found the same pattern. In 1,688 men and women aged 53 to 74, those who took saunas 4 to 7 times a week had a hazard ratio of 0.23 for dying of cardiovascular disease over about 15 years of follow-up, after adjusting for risk factors [2]. For stroke, in 1,628 adults without a prior stroke, 4 to 7 weekly sessions were linked to a hazard ratio of 0.38 over about 15 years [3]. In the men, frequent sauna use was linked to a dementia hazard ratio of 0.34 and an Alzheimer's disease hazard ratio of 0.35 [4].

For longevity, the numbers were more modest. In 2,575 men followed for a median of about 28 years, 3 to 7 sessions a week were linked to a 14% lower risk of death from any cause (hazard ratio 0.86) [5]. Men who combined good fitness with frequent sauna use had some of the lowest risks: a hazard ratio of 0.60 for death from any cause and 0.31 for sudden cardiac death, compared with men who were less fit and used the sauna rarely [9][10].

The randomised trials — the type of study that can show cause and effect — have been much smaller and have measured markers, not deaths or disease. A 2021 meta-analysis of heat therapy found systolic blood pressure about 4 mmHg lower than control [11]. But an 8-week trial of Finnish sauna in 41 adults with stable coronary artery disease found no change in blood pressure or artery function [12], and a 2025 review of 20 randomised trials found no clear effect on most markers, with blood pressure improved only when the whole body was heated [8]. None of these trials tested whether sauna prevents heart attacks, strokes or early death [8][12].

The nuances

The main caveat is the study design: cohort studies can show links, not cause and effect. Frequent sauna users could differ from other people in ways researchers did not measure, although the analyses adjusted for fitness, smoking, blood pressure, cholesterol and socioeconomic status [2][3][4]. Nearly all the strongest findings come from one group of men in eastern Finland studied repeatedly for different outcomes; only some analyses included women, and the population is not diverse [1][2]. Sauna habits were also self-reported once at the start of these long studies, so later changes were not captured [1].

The longevity link is small — about 14% — and some analyses hint that sauna matters most for people who already have other risks: men with high inflammation, high blood pressure or low income had less extra risk of death if they saunaed often, although these interaction findings come from the same cohort and need confirmation [5][13][14].

The lower-risk results mostly come from 4 or more sessions a week; fewer than that showed weaker or no clear links [1][4]. The trials can say this much: sauna appears generally safe for most healthy people and for people with stable heart disease when used sensibly [7].

What this means for you

The evidence does not prove that sauna use extends life or prevents heart disease, and it cannot say what the ideal number of sessions is [1][5]. What it does show is that, in the population studied, people who used the sauna often had fewer heart deaths and lived longer, with no sign of harm for most people [7].

Sauna is generally considered safe for most healthy people and for people with stable heart disease, but people with unstable heart disease, low blood pressure or fainting spells should ask a doctor first [7].

Sensible use matters. In a series of 209 people injured in saunas, most injuries came from slips and falls and from dizziness or fainting, and the authors suggest drinking water before and after a session [6]. Alcohol and sauna are a risky mix: single reports have linked sudden cardiac deaths to dehydration, low blood pressure or heart rhythm problems, some involving alcohol, and one man was badly burned while unconscious with a high blood alcohol level [7][6]. The Sauna topic page has the full safety list.

Go deeper

  • Sauna — Regular sauna use is linked to a lower risk of heart-related death, stroke and dementia in large Finnish studies, and small trials and meta-analyses of heat th…

References

  1. Association between sauna bathing and fatal cardiovascular and all-cause mortality events.. JAMA Intern Med, 2015.
  2. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study.. BMC Med, 2018.
  3. Sauna bathing reduces the risk of stroke in Finnish men and women: A prospective cohort study.. Neurology, 2018.
  4. Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged Finnish men.. Age Ageing, 2017.
  5. Inflammation, sauna bathing, and all-cause mortality in middle-aged and older Finnish men: a cohort study.. Eur J Epidemiol, 2022.
  6. Injuries related to sauna bathing.. Injury, 2023.
  7. Is sauna bathing protective of sudden cardiac death? A review of the evidence.. Prog Cardiovasc Dis, 2019.
  8. Non-acute effects of passive heating interventions on cardiometabolic risk and vascular health: systematic review and meta-analysis of randomized controlled trials.. Am J Prev Cardiol, 2025.
  9. Joint associations of sauna bathing and cardiorespiratory fitness on cardiovascular and all-cause mortality risk: a long-term prospective cohort study.. Ann Med, 2018.
  10. Combined Effect of Sauna Bathing and Cardiorespiratory Fitness on the Risk of Sudden Cardiac Deaths in Caucasian Men: A Long-term Prospective Cohort Study.. Prog Cardiovasc Dis, 2018.
  11. The effect of heat therapy on blood pressure and peripheral vascular function: A systematic review and meta-analysis.. Exp Physiol, 2021.
  12. Finnish sauna bathing and vascular health of adults with coronary artery disease: a randomized controlled trial.. J Appl Physiol (1985), 2023.
  13. Sauna bathing and mortality risk: unraveling the interaction with systolic blood pressure in a cohort of Finnish men.. Scand Cardiovasc J, 2024.
  14. Frequent sauna bathing offsets the increased risk of death due to low socioeconomic status: A prospective cohort study of middle-aged and older men.. Exp Gerontol, 2022.