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Sauna benefits: what the research shows

Most of what we know about regular sauna use comes from a long-running study of middle-aged men in eastern Finland. It found that men who used a sauna more often had fewer fatal heart events and less dementia over two decades. These are associations: they don't prove the sauna caused the difference.

Updated Oct 17, 2026

The Kuopio study

The Kuopio Ischaemic Heart Disease study followed 2,315 men aged 42 to 60 from eastern Finland, recruited between 1984 and 1989, for a median of 20.7 years. The men were grouped by how often they used a (traditional, hot-air) sauna: once a week (601 men), two or three times (1,513) or four to seven times a week (201).

Outcome, 4–7 sessions a week vs once a weekResultSource
Sudden cardiac deathhazard ratio 0.37 (95% CI 0.18–0.75)Laukkanen et al., JAMA Internal Medicine 2015
Fatal coronary heart disease48% lower risk (2–3 sessions: 23% lower)Laukkanen et al., 2015
Death from any cause during follow-up (crude)30.8% vs 49.1% (2–3 sessions: 37.8%)Laukkanen et al., 2015
Dementiahazard ratio 0.34 (95% CI 0.16–0.71)Laukkanen et al., Age and Ageing 2017
Alzheimer's diseasehazard ratio 0.35 (95% CI 0.14–0.90)Laukkanen et al., 2017

The researchers adjusted for smoking, weight, physical activity, blood pressure, cholesterol and income.

What these studies can't tell us

  • Association, not proof. Men who use a sauna daily may differ in ways no adjustment captures (health, wealth, free time). Only trials can show cause and effect, and long-term trials of sauna use don't exist.
  • Men in one region. The cohort was middle-aged Finnish men; the results may not apply to women, other ages or other countries.
  • Traditional sauna only. The study is about Finnish hot-air saunas (typically around 80 °C), not infrared cabins.

Getting the basics right

Typical Finnish practice is rounds of 5–20 minutes in the heat with cooling breaks in between. Drink water, skip alcohol, get out when you feel unwell, and read the sauna safety guide. People with heart conditions, low or high blood pressure, pregnancy or who take medication should ask their doctor before starting.

Sources

  • Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542–548. doi:10.1001/jamainternmed.2014.8187
  • Laukkanen T, Kunutsor S, Kauhanen J, Laukkanen JA. Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged Finnish men. Age Ageing. 2017;46(2):245–249. doi:10.1093/ageing/afw212

Questions and answers

Is a sauna good for your heart?

In a Finnish study of 2,315 men followed for about 20 years, those who used a sauna four to seven times a week had fewer fatal heart events than those who went once a week. That is an association, not proof; people with heart conditions should ask their doctor before using a sauna.

How often should you use a sauna?

The strongest associations in the Finnish research were seen at four to seven sessions a week, but no study shows an ideal number. Many people go two to four times a week; frequency matters less than using it safely.

Do infrared saunas have the same benefits?

Unknown: the long-term Finnish studies looked at traditional hot-air saunas around 80 °C. Infrared cabins work at lower air temperatures and have been studied far less.

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