Key Takeaways
The body releases cortisol in response to stress.Using a sauna increases your body temperature and temporarily stresses your body, which can lead to a rise in cortisol levels in the short-term.Regular sauna use is linked to lower long-term cortisol levels.
Using a sauna causes a short-term spike in the stress hormone, cortisol. However, regular sauna sessions may lead to lower baseline cortisol levels in the long term.
Sauna Bathing Temporarily Increases Cortisol
Sauna temperatures typically range from 176 to 212 degrees Fahrenheit. People often spend 5 to 20 minutes or more in sauna sessions. During this time, your body temperature rises from its typical 98.6 degrees to 102.2 degrees, triggering a stress response and increasing cortisol levels.
Once you are out of the heat, body temperature, cortisol levels, and other biological markers, such as heart rate and blood pressure, gradually return to normal.
Regular Sauna Use Can Lower Your Cortisol Long-Term
Despite short-term cortisol spikes, evidence suggests that regular sauna use may reduce cortisol levels over time.
In a small study of young, moderately to highly active men, four 12-minute sauna sessions per week over 6 weeks led to lower cortisol levels.
Another study found that sauna use followed by cold water immersion lowered cortisol levels in moderately to highly active men. In the study, those with higher baseline cortisol levels showed greater reductions.
Additional Health Benefits of Sauna Bathing
People have been bathing in saunas for relaxation or to boost health for thousands of years. Many claims about it are backed by research, including:
Heart health: One study found that sauna bathing reduced the risk of high blood pressure, cardiovascular diseases (heart and artery diseases), and stroke. A large, long-term Finnish study linked it with a 66% lower risk of sudden cardiac death.Lung function: Evidence suggests that regular sauna bathing boosts lung capacity, volume, and overall function. Researchers found that sauna sessions improved breathing in those with asthma and chronic bronchitis and reduced the risk of certain lung diseases.Joint pain management and headaches: Because it increases blood flow, using a sauna can help ease joint pain and swelling, as with arthritis or fibromyalgia. In addition, researchers found regular sessions reduced the intensity of tension headaches.   Muscle pain and exercise recovery: Just as sauna sessions ease joint pain, they also help with muscle soreness and exercise recovery. In one study, a single session reduced pain and improved physical performance after resistance training.Dementia risk reduction: Researchers found that adults taking 9 to 12 sauna sessions a month had half the dementia risk of those using saunas one or fewer times a week.Mental health: The deep relaxation and physical effects of sauna use may boost mental health. In one study, four weeks of regular sessions improved symptoms in 28 people with mild depression.
Are There Risks?
While sauna bathing is safe for most, there can be risks for certain populations or with improper use. Potential risks include:
Burns: Temperatures that are too high or hot elements in saunas can burn the skin.
Dehydration: Sweating due to high heat can lead to dehydration, causing dizziness, headaches, dry mouth, and other symptoms.
Heat stroke: Prolonged exposure to heat can cause your body to overheat. Common signs include confusion, loss of consciousness, and hot, dry skin.
Dangers with alcohol: Don’t mix alcohol and saunas; this combination can trigger cardiac events and dangerously low blood pressure (hypotension), among other issues.
Heart risks: Heart problems can add risk. If you’ve had a heart attack, low blood pressure, or another issue, talk to your provider about whether saunas are safe.
Risky cold plunges: Some people like to bathe in cold water after a sauna. While safe for healthy people, this can be dangerous—and even fatal—if you have heart issues.
Reproductive effects: Researchers found regular sauna bathing temporarily lowered sperm counts, though these recovered within six months of stopping. Â Â
During pregnancy: Since both the fetus and expectant parent can be impacted by extreme heat, most providers don’t consider saunas safe to use during pregnancy.
