Sauna benefits: what the research actually shows

The short answer

Regular sauna bathing is linked to a lower risk of heart disease, high blood pressure and dementia in large Finnish studies. Those studies followed people for decades, which makes them hard to dismiss, but they were observational. They show that men who used the sauna often were healthier over time, not that the sauna caused it. For most healthy adults, a traditional sauna is safe. People with some heart conditions should ask a doctor first, and no one should combine the sauna with alcohol.

Where the evidence comes from

Almost all the long-term data comes from the Kuopio Ischaemic Heart Disease study in eastern Finland. It enrolled about 2,300 middle-aged men in the 1980s, asked how often and how long they used the sauna, and then followed them for more than 20 years. In Finland the sauna is part of ordinary life, so the study could compare men who went once a week with men who went almost every day.

That design has two strengths: a large group and a very long follow-up. It also has clear limits. Everyone in the main studies was a Finnish man, the sauna habits were measured once at the start, and people who use the sauna often may differ in other ways that the researchers could not fully adjust for.

Heart and circulation

The best-known result was published in JAMA Internal Medicine in 2015. Compared with men who used the sauna once a week, men who went four to seven times a week had a 63% lower risk of sudden cardiac death, a 50% lower risk of dying from cardiovascular disease and a 40% lower risk of dying from any cause over about 21 years. Longer sessions were also linked to lower risk: men who stayed in for more than 19 minutes had about half the risk of sudden cardiac death of those who stayed under 11 minutes. (Laukkanen et al., JAMA Internal Medicine, 2015)

A review of the evidence in Mayo Clinic Proceedings in 2018 described possible reasons. A hot sauna raises the heart rate in a way that resembles light to moderate exercise, and repeated use is associated with more flexible blood vessels and lower blood pressure. The authors also pointed out what is still uncertain and called for controlled trials. (Laukkanen, Laukkanen and Kunutsor, Mayo Clinic Proceedings, 2018)

Blood pressure

In the same Finnish group, men without high blood pressure at the start who used the sauna four to seven times a week were about 47% less likely to develop it over roughly 25 years than men who went once a week. The difference for two to three sessions a week was smaller and not statistically clear. (Zaccardi et al., American Journal of Hypertension, 2017)

Brain health

A 2016 study in Age and Ageing found that men who used the sauna four to seven times a week had about a 66% lower risk of dementia and a 65% lower risk of Alzheimer's disease over 20 years than men who went once a week. Again, two to three times a week showed a smaller difference that could be due to chance, and the authors said more research is needed to understand why. (Laukkanen et al., Age and Ageing, 2016)

Other claims

Reviews mention possible benefits for breathing, muscle and joint pain, and how people feel after a session. The evidence for these is thinner, often from small studies. (Hannuksela and Ellahham, American Journal of Medicine, 2001)

Some popular claims have little or no support:

• Detox. Sweating does not meaningfully clear toxins. Your liver and kidneys do that work.
• Weight loss. The weight you lose in the sauna is water, and it comes back when you drink.
• Infrared is healthier. Infrared saunas run cooler, usually around 104 to 140°F of air temperature, and most of the long-term research is on traditional Finnish saunas. There is no strong evidence that infrared is better. (The Conversation, 2018) Read more in Finnish vs infrared saunas.

What about the cold plunge?

Many US bathhouses pair the sauna with a cold plunge. The research on cold water is much younger. A 2025 review of 11 trials found that cold immersion was followed by lower stress about 12 hours later and a short spike in inflammation, and that a month of daily cold showers was linked to fewer sick days at work, but the evidence was limited and mostly from men. (Cain et al., PLOS One, 2025) See how to go from sauna to cold plunge.

Who should be careful

A traditional sauna is well tolerated by most healthy adults and children, according to a review in the American Journal of Medicine. The same review lists people who should not use it: anyone with unstable angina, a recent heart attack or severe aortic stenosis. (Hannuksela and Ellahham, 2001)

Talk to a doctor before you start if you:

• have heart disease, very high or very low blood pressure, or have fainted before
• take medicine that affects blood pressure, heart rate or sweating
• are pregnant, especially if the pregnancy is not straightforward
• have a condition that makes it hard to sense heat or to get up quickly

And for everyone:

• Skip alcohol before and during the sauna. Drinking raises the risk of low blood pressure, an irregular heartbeat and sudden death in the sauna. (Hannuksela and Ellahham, 2001)
• Drink water before and after.
• Get out if you feel dizzy, sick or confused, and cool down slowly.

This guide explains research. It is not medical advice for your situation.

How often and how long

In the Finnish studies, the biggest differences were between men who went once a week and men who went four to seven times a week, with sessions often longer than 19 minutes in total. That is a description of what Finnish men did, not a prescription. If you are new to the sauna, start with shorter rounds and build up. Our guide to how long to stay in a sauna has practical numbers.

Where to try it

You can find traditional and wood-fired saunas in every city we cover, from New York and Los Angeles to Minneapolis, where wood-fired saunas set up by the lakes each winter. For the hottest traditional rooms, look at the wood-fired saunas and Russian banyas we list.