The short answer
Long-running studies from Finland link regular sauna use with a lower risk of heart disease, high blood pressure and dementia, with the biggest differences in people who used a sauna four or more times a week. But these studies show links, not proof, and were done mostly on middle-aged men using traditional 80 to 100°C saunas. Saunas do not detox you, and any weight lost is water.
Sauna brands make a lot of health claims. Some are backed by solid research, some are stretched, and some have no evidence at all. This guide sets out what the studies actually found, how strong that evidence is, and what it means if you are using a portable sauna at home.
What happens in your body
Sitting in a hot sauna raises your skin and core temperature. Your heart rate rises, blood vessels in the skin widen to release heat, and you sweat. A 2018 review in Mayo Clinic Proceedings describes heart rates of 120 to 150 beats a minute in a traditional sauna, a response it compares with moderate to high-intensity physical activity such as walking. Unlike exercise, though, your muscles are not working.
Heart health
The best-known study followed 2,315 middle-aged men in eastern Finland for around 20 years. Compared with men who used a sauna once a week, those who used one more often had a lower risk of dying from heart disease:
| Sauna use (vs once a week) | Sudden cardiac death | Fatal heart disease | Death from any cause |
|---|---|---|---|
| 2–3 times a week | 22% lower | 23% lower | 24% lower |
| 4–7 times a week | 63% lower | 48% lower | 40% lower |
Longer sessions, over 19 minutes, were also linked with a lower risk of sudden cardiac death than sessions under 11 minutes.
These are associations. Men who use a sauna most days may differ in other ways, such as fitness, income or how relaxed their lives are. The researchers themselves say more studies are needed to understand why the link exists.
Blood pressure
In a 2017 study of 1,621 men from the same Finnish group who did not have high blood pressure at the start, those who used a sauna two to three times a week were about 24% less likely to develop it over the next 22 years, and those using it four to seven times a week about 46% less likely, compared with once a week. Heat widens blood vessels and may make arteries less stiff over time, which is one possible explanation.
Brain health
A 2016 study of the same 2,315 men found that those who used a 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, compared with once a week. For two to three times a week, the difference was smaller and not statistically significant. This is an interesting finding, but it comes from one group of Finnish men and has not been proven in trials.
Relaxation, sleep and recovery
Many people simply find a sauna relaxing, and that is a perfectly good reason to use one. The 2018 review also reports links with better quality of life and relief from muscle and joint aches, and some people find it helps them wind down before bed. The evidence here is much weaker than for heart health, and mostly comes from small studies and people’s own reports.
Weight loss and “detox”
Weight loss: you can step out of a sauna noticeably lighter, but that is water lost through sweat. It comes straight back when you drink, which you should. A sauna does not burn fat in any meaningful way.
Detox: your liver and kidneys clear waste products from your body. Sweat is mostly water and salt, and there is no good evidence that a sauna “flushes out toxins”. Be wary of any brand that promises it does.
Do portable saunas count?
This is the honest caveat for anyone buying a portable sauna. The studies above were done on traditional Finnish saunas at 80 to 100°C. Portable steam tents usually run at about 45 to 50°C (humid air makes it feel hotter), dry heat pods up to about 85°C, and sauna blankets heat you through infrared.
They all raise your body temperature and make you sweat, so it is reasonable to expect some similar effects, but there is no good research showing that a portable sauna gives the same results as the Finnish studies. If health is your main reason for buying, a dry heat pod comes closest to traditional sauna temperatures. Our portable vs traditional sauna guide compares the two.
The bottom line
- The research on regular sauna use and heart, blood pressure and brain health is encouraging, but it shows links, not proof.
- Most of it comes from middle-aged Finnish men using traditional saunas several times a week.
- Saunas do not detox you, and any weight lost is water.
- Enjoying the warmth and relaxation is a good enough reason on its own.
Sauna use is not suitable for everyone. Read who should not use a sauna before you start, and speak to your GP if you have a health condition.
Questions
What are the proven benefits of a sauna?
No sauna benefit is fully proven. The strongest evidence comes from long-running Finnish studies, which link regular sauna use with a lower risk of heart disease, high blood pressure and dementia in middle-aged men. These studies show associations, not cause and effect.
How often should you use a sauna for health benefits?
In the Finnish studies, the biggest differences were seen in men who used a sauna four to seven times a week, compared with once a week. Two to three times a week was also linked with lower risk, but by less.
Does a sauna help you lose weight?
Not in a lasting way. The weight you lose in a sauna is mostly water from sweating, and it comes back as soon as you drink. A sauna is not a substitute for diet and exercise.
Does a sauna detox your body?
Your liver and kidneys remove waste products, not your sweat. There is no good evidence that sweating in a sauna removes meaningful amounts of toxins.
Do infrared saunas and sauna blankets have the same benefits?
We do not know. The best-known research was done on traditional Finnish saunas at 80 to 100°C. There is much less research on infrared saunas, and very little on sauna blankets or portable steam tents.
Sources
- Laukkanen et al. (2015). Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine (summary via EurekAlert)
- Zaccardi et al. (2017). Sauna bathing and incident hypertension: a prospective cohort study. American Journal of Hypertension
- Laukkanen et al. (2016). Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men. Age and Ageing
- Laukkanen, Laukkanen and Kunutsor (2018). Cardiovascular and other health benefits of sauna bathing: a review of the evidence. Mayo Clinic Proceedings
- Hannuksela and Ellahham (2001). Benefits and risks of sauna bathing. American Journal of Medicine
This guide is general information, not medical advice. If you have a health condition, are pregnant or take regular medication, speak to your GP before using a sauna.