Saunas have been used for thousands of years around the world. In Finland, it’s common to have a sauna at least once a week. People use saunas for relaxation and fun. Studies show that they also have health benefits, especially when the user spends at least 20 minutes in sauna bathing. However, there are certain groups of people or people with particular medical conditions for whom the recommended maximum length of time in the sauna may vary.
What Are the Health Benefits of Sauna Bathing?
Regular use of dry saunas — both traditional and infrared saunas (which uses light instead of heat to warm your body without heating the air around you) — can improve your cardiovascular health, improve your breathing if you have allergic or respiratory disorders, lower your risk of stroke, help modulate your immune system, and help control high blood pressure, says Joy Hussain, MD, clinical director of Health with Joy Pty Ltd, an integrative medical practice promoting wearables, wellness, and evidence-based thermotherapy in Brisbane, Australia. Hussain also leads clinical and lab-based research on sauna bathing and its effects on health.
Most research has been done in Finnish or traditional saunas. These saunas use dry heat, and people in the sauna may use heated stones that they moisten to increase humidity. The temperature is usually around 160 F. People typically stay in the sauna for at least 5-20 minutes.
Infrared saunas could be a good option for people who find the heat of a traditional sauna overwhelming.
Blood pressure. Several studies have linked traditional sauna use to reduced blood pressure and a lower risk of high blood pressure. Short-term benefits include lowered blood pressure for 30 minutes after sauna bathing, with and without exercise, in people both with and without high blood pressure. Long-term benefits of lower blood pressure have been seen in people who use saunas more often — three to four times a week compared with once weekly. These findings come from large Finnish studies tracking cardiovascular risk, mostly in men.
Cardiovascular disease. Studies show that regular sauna use when combined with exercise reduces the risk for cardiovascular diseases (heart and blood pressure diseases). Many clinical trials have been done in Japan on Waon therapy, in which the person spends 15 minutes in an infrared sauna, typically set at 140 F, followed by 30 minutes of lying down under a warm blanket. “Most of the interventional studies detail the effects — mostly benefits –— to those with cardiovascular disorders, especially those diagnosed with heart failure,” Hussain says.
We need more research to confirm whether sauna bathing cuts the risk of neurocognitive diseases or helps counter their causes, such as heart disease. One theory is that the relaxing environment of the sauna affects your brain in positive ways.
Lung function. One study tested the effects of sauna bathing on people with pulmonary disease (lung disease). It found that saunas helped ease or prevent colds, chronic bronchitis, asthma, and pneumonia.
We need more research, but there’s also some evidence that saunas might help with:
- Musculoskeletal disorders
- Headache disorders
- Chronic tension
- Psoriasis
Chronic pain. “There’s evidence suggesting regular saunas might also benefit those with chronic pain syndromes,” says Hussain, citing a recent Korean study and older Japanese studies on lower back pain.
Can Saunas Help You Lose Weight?
Saunas can certainly lead to short-term weight loss due to acute water loss through sweating. A study done on nearly 700 people found that after a 30-minute dry sauna session, the participants lost about 1% of their water weight. It found that you could sweat more depending on several factors, including how long you are in the sauna, how much water you’ve had, and more.
In a small study, 45 men did four dry sauna sessions of 10 minutes each. Researchers measured their body mass before and after the saunas. They found that the men lost almost a pound and a half overall. But this weight loss may only be temporary.
“Jockeys, wrestlers, boxers, and other weight-sensitive athletes have been using saunas to manipulate their weight for such purposes for decades,” says Hussain. “However, to my knowledge, there is no rigorous evidence linking long-term sauna use to long-term weight loss.”
How Long Should You Stay in a Sauna?
Most clinical studies focus on people who bathe in the sauna for 20 minutes or less. However, evidence recognized by the American College of Cardiology suggests that sauna bathing for longer than 19 minutes increases the protection against various heart issues by more than 50%.
If you’re just starting, ease into it by using the sauna for 5-10 minutes at a time. A good goal is to slowly build up to sessions of about 15-20 minutes.
How Often Should You Use a Sauna?
Studies have found that visiting the sauna more than once a week increases health benefits and overall longevity. Most of the data around sauna usage highlights the fact that more weekly visits to the sauna over a long period add to the benefits.
“There’s no one-size-fits-all answer,” Hussain says. “If it’s for rest and relaxation, then it depends on the individual and their needs. Some [people who use] saunas bathe most every day, others once or twice a week or fortnight, and others only once a month or a few times a year.”
Studies continue to gauge the number of sauna sessions over a period of weeks that benefit people most when it comes to sauna bathing for particular conditions. Some have shown marked results, Hussain says, citing a study of men in Eastern Finland. “If sauna bathing is to improve general heart health (that is, to reduce risk of heart attacks, stroke, and life-threatening cardiac events), then sauna bathing at least three times weekly, preferably fouror more times weekly, is associated with dramatic reductions in all these types of cardiac events and in fact improved longevity,” compared to those who reported sauna bathing only once a week, she says.
Should I Use the Sauna Before or After a Workout?
It depends on the individual and their reasons to use the sauna. “If you’re an athlete, then using the sauna after training makes sense, with plenty of evidence linking saunas to better muscle recovery in swimmers, cross-country skiers,” and so on, Hussain says. “If you are using the sauna for stress reduction or pain relief, then each person will be different.” She says she loves to hop into the sauna before and after swimming — before, so the cold water is not such a shock to the system, and after, for more relaxation.
Research is currently being done into combining sauna bathing with showering and cold plunges, which fall under the category of “contrast bathing.”
Do Saunas Have Any Risks or Dangers?
Research shows that responsible sauna use carries few risks. In Finland, there are almost 2 million saunas for a population of 5 million people. Even though Finnish people spend a lot of time in the sauna, the rate of deaths related to sauna use is meager.
However, drinking alcohol, taking drugs, or taking medications that interfere with the body’s ability to regulate its temperature is risky. Most people who die in the sauna have either been drinking heavily or are hungover. We don’t yet completely understand what drinking does to the body when you’re in the sauna. It seems to cause problems with your body’s ability to stabilize blood pressure, leaving you vulnerable to arrhythmias or irregular heartbeats.
People who have recently experienced the following health issues should also avoid saunas:
- Severe aortic valve stenosis. This is when your heart’s aortic valve doesn’t allow blood to flow freely. Saunas can boost your heart rate, which could cause your aortic valve to become blocked.
- General chest pain (angina pectoris). If you’ve been having chest pain, stay out of the sauna until your doctor has examined you.
- Heart attacks. Avoid saunas if you’ve recently had a heart attack or a stroke. It’s best not to risk overexerting your heart.
Who Should Not Use a Sauna?
Due to the extreme heat and dehydration risks of sauna bathing, the following people should be sure to either use saunas with extreme care or not at all:
Older people. People aged 65 years or older should be wary of heatstroke in the sauna. Heatstroke has previously caused sauna deaths in that demographic. People aged 65+ years generally experience a more extreme reaction to heatstroke as their body’s internal temperature regulation is weakened.
Children younger than 7 years. Finnish children are often introduced to the sauna during infancy. But parents rarely let children go into the sauna unsupervised until they are older than 7. Before that, parents closely monitor their children before, during, and after bathing in the sauna. Very young children have a less developed internal temperature system and can be more prone to getting heatstroke than adults. Make sure you monitor your children during and after sauna bathing, and take them out if they become too overheated.
People with seizure disorders. It has been found that many seizure disorders either interfere with your internal temperature or, like febrile seizures, can be triggered by a sudden change in temperature. If you often get seizures or are diagnosed with a seizure disorder, you should avoid going into the sauna altogether.
People who have had a recent sunburn or have extensive skin lesions from whole body eczema or psoriasis. “These conditions impact our skin’s ability to hold moisture content adequately, and so one runs a higher risk of becoming dehydrated quickly,” Hussain says.
People who have any eye or eyelid irritation. Sauna use can sometimes irritate the eyes, especially for people with existing eye or eyelid conditions. “In a global sauna survey I conducted several years ago, I was surprised how many respondents complained about eye irritations either inside the sauna or post-sauna, with a few respondents even mentioning hospitalizations for their eye condition post-sauna,” Hussain says.
Sauna Safety Tips
If you are thinking about using a sauna, here are some tips to consider:
- Avoid drinking alcohol before or during sauna activities.
- Don’t use a sauna alone, and always let someone know you are using it.
- Don’t stay in the sauna if you feel dizzy, overheated, or dehydrated to prevent injury.
- If you haven’t used saunas much in the past, you can start by limiting your sauna usage to 20 minutes or less.
Signs of dehydration include:
- Thirst
- Dry or sticky mouth
- Not peeing very much
- Dark yellow pee
- Dry, cool skin
- Headache
- Muscle cramps
- Confusion
Takeaways
Sauna bathing is generally a safe and healthy activity, especially when you regularly spend at least 20 minutes per session. If you’re new to using a sauna, start with less time, about 5-10 minutes, and increase your time gradually.
Never sauna bathe alone or without letting someone know when you intend to use it.
Avoid using the sauna if you’ve had a heart attack in the past few months, have a seizure disorder, sunburn, or are dehydrated.
Sauna FAQs
Is it OK to use the sauna every day?
Everyday sauna use is generally safe if done sensibly and not excessively. “Many in Finland already do so,” Hussain says.
Is it better to use a sauna before or after a shower?
There’s no single rule about whether it’s better to use a sauna before or after a shower. Shower protocols and advice differ, but some large health facilities, such as the YMCA, require sauna users who’ve just worked out to shower and change into clean clothes before going into the sauna.
What should you wear in a sauna?
“This depends mostly on cultural context and personal preferences,” Hussain says. “It’s probably a good idea not to wear anything that significantly impedes whole body sweating, to avoid hyperthermia.”
Is it better to sauna before or after a cold plunge?
Currently, there’s no clear evidence on whether it’s better to use a sauna before or after a cold plunge. “I’ve noticed more studies looking at the effects of ‘contrast therapy’ or intermixing sauna with cooling exposures (cold water immersion, cold showers, and so on,” Hussain says. “A lot more research needs to be done in this space before making any conclusions, though.”
