Published 3rd February 2025
Can saunas really benefit your health?
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While saunas were first enjoyed thousands of years ago in Finland, their popularity has now spread to health and wellness circles further afield.
While they are undoubtedly relaxing, many attribute significant health benefits to regular sessions.
Some claim saunas can improve blood flow and support lung and heart health, and some even claim they’re as important as exercise for good health.
Here, we’ll look at the latest research and explore whether the evidence stacks up.
While heat therapies come in many forms, such as hot tubs, steam baths, and the newer infrared saunas, we’ll mostly focus on traditional Finnish saunas as they’ve garnered the most scientific attention.
The results of the research we describe below are very encouraging. However, we need to take them with a pinch of salt. So, we’ll mention some limitations along the way and then dive a little deeper toward the end.
We’ll also explain how to stay safe if you decide to enjoy a sauna.
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Blood pressure
High blood pressure, also called hypertension, is a common issue and the leading risk factor for death from cardiovascular disease across the globe. It affects an estimated 1.28 billion adults, globally.
Many studies have investigated whether saunas might improve hypertension, but most focus on people with an existing risk factor for heart disease.
Also, most have only assessed the blood pressure-lowering effects directly after taking a sauna, rather than the longer-term effects. With that said, the results are encouraging.
For instance, a 2018 study recruited 102 adults with one or more markers of cardiovascular risk. After a 30-minute sauna, the scientists measured significant declines in blood pressure.
Thirty minutes later, their blood pressure was still lower than before taking the sauna.
Another study, involving 16 people with untreated hypertension, compared the effects of no intervention, sauna, and sauna plus exercise. They found that sauna alone and sauna with exercise reduced blood pressure for at least 2 hours.
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While most research has focused on the short-term effects of sauna bathing, there is some evidence for longer-lasting benefits. A 2017 study followed more than 1,600 males aged 42 to 60 without hypertension for more than 2 decades.
In their analysis, the scientists adjusted for a range of factors, including fitness level, smoking, and alcohol consumption.
Amazingly, they found that, compared with one sauna session per week, those who had 4–7 saunas each week had a 47% decreased likelihood of developing hypertension.
While the researchers adjusted for a range of variables, it’s still possible that other factors were involved.
One explanation might be that people with enough free time to have a sauna every day are less stressed than those who can only fit in one each week. Still, 47% is a large effect.
Heart health
Some scientists have explored the cardiovascular benefits of saunas more generally. One study followed more than 2,300 people for around 20 years.
They adjusted their analysis to account for factors associated with heart disease, like smoking, age, cholesterol levels, type 2 diabetes, level of fitness, and body mass index (BMI).
Again, they found that those who had more saunas per week had a lower risk of:
sudden cardiac death
fatal coronary heart disease
fatal cardiovascular disease
death by any cause
They also found that people who stayed in the sauna longer per session had greater benefits.
Another group of researchers studied stroke in more than 1,600 middle-aged and older adults over 15 years. They found that people who had 4–7 sauna sessions each week had a 62% lower risk of stroke than those who had one sauna per week.
Neurodegenerative conditions
Neurodegenerative conditions involve a slow, irreversible decline in brain health. They include Parkinson’s disease and dementias, like Alzheimer’s.
These conditions often involve changes to blood flow in the brain, so some scientists have wondered whether saunas' benefits to heart health might also protect against them.
The first study to investigate this relationship was published in 2017. The scientists followed 2,315 healthy men aged 42–60 for around 20 years.
Again, they controlled their analysis for a range of factors and compared those having just one sauna session per week with those having 4–7. They found that those having regular saunas had more than 60% reduced risk of developing dementia during the follow-up.
Lung health
Beyond circulation, it seems that saunas may also support lung health. There’s evidence that regular saunas are linked to a reduced risk of respiratory conditions and lung infections, including pneumonia.
Similarly, some small studies from the 1980s suggest that saunas might help relieve the symptoms of obstructive pulmonary disease, a common condition caused by lung damage that makes breathing difficult.
The take-home message
Overall, there’s evidence that regularly taking a sauna is linked to health benefits, including cardiovascular and lung health.
The authors of one review conclude that “3 to 7 sauna sessions per week with each session lasting about 15 to 20 minutes is associated with the most health benefits.”
However, most of the research has been conducted in Finland, and may not translate to other populations.
In fact, a great deal of the research mentioned above came from one group of people from Eastern Finland who were involved in the long-running Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study.
This type of study is called an observational cohort study. They are an important scientific tool, but they also have some inherent limitations, such as:
Some factors that influence the results may not be measured.
Reverse causation: It may not be that saunas improve health; rather, it could be that healthier people choose to have saunas.
Regression dilution bias: This is caused by errors when measurements are taken and can influence the final results.
These studies can’t prove causation, just an association.
Also, Finland is a relatively wealthy country, and we know that socioeconomic factors play a significant part in the risk of many diseases.
Additionally, much of the research was conducted decades ago and focuses on middle-aged males. This means that the benefits for people of different ages and for females are less clear.
Because of these factors, the authors of another review conclude:
“Well-designed [randomized controlled trials] with long-term follow-up will still be needed to confirm whether the observed associations reflect a true causal effect of frequent sauna bathing on these health conditions, and more studies are warranted to find whether regular sauna bathing could produce longer-term changes in cardiovascular health.”
In general, though, taking a sauna is safe for most people, so if you enjoy them, go for it. But there are some things to be wary of.
Sauna safety
You should speak with your doctor before taking a sauna if you are pregnant or have:
uncontrolled high blood pressure
any form of heart disease
For healthy people, here are some other tips to keep you safe:
Before, during, and after a sauna, avoid alcohol and any medicines that reduce your ability to sweat.
Don’t stay in the sauna for longer than 15–20 minutes.
Try to cool down gradually once you’ve finished the sauna.
After a sauna, make sure to rehydrate to replace fluids lost through sweating.
If you’re sick or have an infection, don’t have a sauna.
If you start to feel unwell in the sauna, leave straight away.
