Your Brain

The Benefits of Saunas for Stress, Sleep, and Mental Health

If you are like most people, sauna use has been an experience associated with relaxation, but sauna bathing may offer benefits that reach well beyond relaxation. Regular sauna bathing, beyond relaxation, may result in stress reduction, improved sleep, and potentially decreased risk of dementia; thus we have barely scratched the surface in terms of understanding just how sauna bathing may support our brains.

Let’s consider the effects of heat on the brain.

Saunas and Neurocognitive Health

One of the most compelling areas of sauna research has been sauna bathing and long-life brain health. Because Finland has so many saunas, several studies conducted in Finland show that sauna bathing is associated with decreased odds of dementia and Alzheimer’s disease.

One paper examined a long-term sample of 2300 men over 42-60 years of age with a 20-year follow-up. They found that men who sauna bathed 4-7 times per week had a 66% reduced risk for developing dementia and a 65% reduced risk of developing Alzheimer’s disease as compared to men who sauna bathed one time per week. These results were statistically significant and remained significant after adjusting for age, fitness, lifestyle and health factors.

Another paper pooled data from nearly 14,000 Finnish adults with an average follow up of 39 years. The authors found similar results. Participants who sauna bathed 9-12 times per month had a reduced risk for dementia of 47% over first two decades of follow up, and the authors note the reduction in risk was substantial even decades later.

Potential Ways Heat May Protect the Brain

Though researchers are still excavating the exact pathways, there are multiple possibilities that might be useful for explaining the link between sauna use and brain health.

Better Heart & Vessel Function: Good circulation is important to brain health. Sauna use has been shown to improve vascular function, decrease arterial stiffness, and reduce blood pressure, all of which likely correspond to a lower likelihood of cognitive decline.

Decreased Inflammation & Oxidative Stress: Chronic inflammation and oxidative stress contribute to neurodegenerative diseases. Sauna use is associated with decreased levels of inflammatory markers, such as C-Reactive Protein (CRP) and an increase in antioxidant activity from in sauna culture to a non sauna culture.

Heat Shock Proteins (HSPs): HSPs are “helpers” produced by the body during sauna use that could play a part in support of protein folding and avoiding misfolded protein clumping that is associated with conditions like Alzheimer’s and Parkinson’s disease.

Calmness of the Autonomic Nervous System: Saunas may positively influence the autonomic nervous system, allowing development of both mental calm and physical resilience.

Cultural and Psychological Components: These are often difficult to quantify, but the combination of relaxation, routine, and social component of sauna culture would understandably help support mental health and cognitive reserve.

A note about temperature: Moderate, sauna temperature appears to offer benefits, but some studies suggest extreme heat (>100° C) may increase dementia risk, and the risk may increase over time. More is not always better, and that is very true for the brain.

Stress, Anxiety, and Mood Support

Many individuals reflexively head to a sauna when they are looking to unwind, and science is increasingly supporting this instinct. Sauna bathing initiates an array of mental and physical reactions that can diminish stress and alter the perception of mood.

People who regularly use saunas report experiencing benefits that include:

A feeling of mental clarity
Emotional calm
A general sense of well-being

Clinical evidence backs this up too: A randomized controlled trial in people with mild depression showed that four weeks of sauna sessions improved complaints like fatigue, irritability, and relaxation scores.

In people with chronic fatigue syndrome, infrared sauna sessions significantly decreased fatigue and anxiety symptoms. Even in individuals with chronic pain, sauna use helped reduce anger and emotional distress.

You’ve likely heard someone who’s wanting to lose weight say something like, “I’m going to the sauna to burn fat and lean out.” The act of sitting in a heated room and increasing your heart rate while sweating profusely actually tends to burn fat; after all, you typically walk away feeling “lighter.” But does sweating actually make you lose fat?

Saunas make you sweat and that can most definitely alter your weight temporarily but that can change due to more than just fat loss. Let’s investigate the science behind saunas, body fat, and changes in weight.

The Hormonal Aspect of Relaxation

Sauna bathing also causes a cascade of hormone and nervous system activity:

When the body is exposed to heat, endorphins, the body’s natural feel-good chemicals, increase.
It also activates the sympathetic nervous system, increasing norepinephrine mimicking high-intensity exercise.
The hypothalamus-pituitary-adrenal (HPA) axis which helps regulate stress and mood also gets activated.

These hormonal and neural adaptations may account for the fact that sauna users often feel more emotionally balanced, happy, relaxed, and occasionally euphoric following a sauna session.

Sleep: One of the Most Subtle Benefits of Sauna

Many sauna users will attest to the ability of heat to improve sleep, and surveys indicate that the sauna may be linked to that improvement.

For example, in a study of middle-aged urban Finland adults, sauna bathing was the most often reported behavior associated with improved sleep quality. While this has not been demonstrated in randomized trials, it is consistent with our understanding of body temperature and sleep regulation.

Here is why it may work:

When the body’s core temperature is raised-whether that is in a warm bath or sauna, the body will then experience a gentle drop in temperature, and this drop in temperature is associated with falling asleep quickly and having restful, deep sleep.

Conclusions

To someone looking in, a sauna session may seem like a very simple thing to do self-care in and of itself, but the mechanisms by which it may affect the brain are not so simple. From stress relief, improving sleep, and possibly reducing risk of dementia, sauna use has a fascinating suite of mental health benefits supported by emerging science.

And this is only the beginning.

If you’re curious about more the ways sauna bathing promotes health, both on a cellular and system level, please continue following the Health Benefits of Sauna series.

Sauna Health Benefits Research Resources

We asked, what research is actually out there? How do we know what is sales words, and what is grounded research. Through that, we decided to compile a library of all the literature on the health benefits of sauna.

Sauna & Heart Health

Sauna benefits to vascular endothelial cardiac function

Vascular endothelial function improved: Sauna therapy significantly increased flow-mediated dilation (%FMD), showing better blood vessel function.
Cardiac stress decreased: Levels of BNP (a marker of heart failure severity) dropped after two weeks of sauna treatment.
Clinical symptoms improved: 17 out of 20 patients reported better symptoms and overall cardiac function after repeated sauna sessions.

Sauna & Heart Health

Sauna effect on heart rate variability

Significant plasma volume increase: Post-exercise sauna use expanded plasma volume by about 18% after just four sessions.
Heart rate and HRV changes were small or unclear: Only minor reductions in resting heart rate and small shifts in HRV markers were observed, with unclear correlations to plasma volume.
Sauna enhanced training adaptation: Adding sauna to normal training improved physiological capacity in trained cyclists beyond training alone.

Sauna & Arthritis

Infrared Sauna in Arthritis and Spondylitis

Pain and stiffness significantly reduced: During IR sauna sessions, both RA and AS patients showed marked decreases in pain and stiffness (p < 0.05 and p < 0.001, respectively).
No adverse effects or disease flare-ups: Treatments were well tolerated, with no signs of increased disease activity or other side effects.
Short-term comfort, modest long-term benefit: Patients reported feeling comfortable and relaxed during and after sessions. Clinical improvements persisted during treatment but faded post-therapy.

Sauna & Heart Health

Advertising in Saunas and Positioning

Digital promotion gained momentum: Social media emerged as a powerful channel for business growth, offering wide reach and precise audience targeting for tailored advertising.
Marketing strategies adapted post-crisis: The health crisis reshaped the economy and reduced ad spending, pushing companies—including sauna brands—to prioritize customer acquisition through focused advertising efforts.
Medicinal benefits reinforced: Positioning centered on health advantages, with studies showing that 2–3 or ≥4 weekly sauna sessions significantly reduced the risk of respiratory diseases compared to ≤1 session per week.

Sauna & Exercise Recovery

Effects of Thermal Modalities on Exercise Recovery

Effectiveness depends on participant type: Warm Water Immersion (WWI) was found to be more effective for athletes in increasing recovery and preventing muscle cell damage. Conversely, Infrared Sauna (IRS) and Traditional Sauna (TRS) were more effective for recovery in nonathletes.
Significant reduction in fatigue markers: All recovery modalities played a role in reducing the blood lactate level (BLL) after physical activity, and all modalities were effective in significantly reducing heart rate (HR) in both groups after exercise.
WWI minimized perceived pain: The WWI modality resulted in the least amount of pain in both athletes and nonathletes. Passive recovery (PAS), in contrast, tended to cause severe pain.

Sauna & Mortality

Sauna Use and Mortality Reduction

High frequency reduces overall and cardiovascular death: Increased frequency of sauna bathing is associated with a reduced risk of sudden cardiac death (SCD), fatal coronary heart disease (CHD), fatal cardiovascular disease (CVD), and all-cause mortality.
Maximum protective effect seen in frequent users: Compared with men bathing once per week, those reporting 4 to 7 sauna sessions per week had a significantly lower adjusted hazard ratio for SCD (0.37) and experienced a 40% reduction in all-cause mortality.
Longer duration also lowers SCD risk: Longer sauna sessions were inversely associated with fatal cardiac events; sessions lasting more than 19 minutes were linked to a 52% lower risk of SCD compared to sessions lasting less than 11 minutes.

Sauna & Therapies

Benefits and Scope of Passive Heat Therapies

Finnish Sauna is the most studied modality: Finnish saunas are the most widely studied passive heat therapy, characterized by high temperatures (80–100°C) and dry air (10–20% relative humidity).

Demonstrated health benefits and disease prevention: Finnish saunas have robust evidence showing they decrease the risk of hypertension, cardiovascular disease (CVD), dementia, and respiratory conditions. They may also improve sleep, mental well-being, and longevity.

Potential for synergistic effects and mechanism: Passive heat therapies may augment the beneficial effects of physical activity and their positive effects are linked to anti-inflammatory, cytoprotective, and anti-oxidant properties.

Sauna & Respiratory Diseases

Sauna Reduces Respiratory Diseases

Lower respiratory disease risk: Men taking 2–3 sauna sessions per week showed a 27% reduction in respiratory disease incidence compared to ≤1 session.

Stronger benefits with higher frequency: Those bathing ≥4 times weekly had up to a 41% lower risk, indicating a dose-response relationship.

Pneumonia risk reduced: Frequent sauna users experienced 28–37% lower pneumonia incidence after long-term follow-up and risk adjustment.