What to Know About Saunas and Your Health

Medically Reviewed by Ross Brakeville, DPT on September 13, 2023
5 min read

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 have found that they also have health benefits, especially when the user spends at least 20 minutes 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 be different. 

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 the humidity. The temperature is usually around 160° F. People typically stay in the sauna for at least 5 to 20 minutes.

There have been a few studies on infrared saunas, which use light instead of heat to increase your body temperature without warming up the air around you. These saunas could be a good option for people who find the heat of a traditional sauna overwhelming. But we need more research into the health benefits of infrared saunas. 

Blood Pressure. ‌At least four studies have linked sauna use to reduced blood pressure and lower risks of high blood pressure. But it’s unclear whether saunas affect blood pressure in the long term or just temporarily.

Cardiovascular Disease. Several studies have shown that regular sauna use (along with exercise) reduces cardiovascular diseases (heart and blood pressure diseases).

Neurocognitive Disease. Neurocognitive disease includes dementia and other issues that lead to reduced brain function. It’s often caused by heart problems, inflammation, and oxidative stress (which happens when there are too many harmful molecules called free radicals in your body). 

We need more research into whether sauna bathing reduces the risk of neurocognitive diseases or helps to 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 to ease or prevent colds, chronic bronchitis, asthma, and pneumonia. 

We need more research, but there’s also some evidence that saunas might help with

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%.

It was also found that visiting the sauna more than once a week increased similar health benefits and overall longevity. Most of the data around sauna usage emphasizes the fact that more weekly visits to the sauna over a long period increases its benefits.

Research has shown 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, ingesting 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 increase 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. ‌

In addition, 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 under the age of seven. Finnish children are often introduced to the sauna during infancy. However, parents rarely let children go into the sauna unsupervised until they are older than seven. 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 susceptible to heatstroke than adults. Make sure you monitor your children during and after sauna bathing, and take them out if they become too overheated. 
  • Pregnant women. Pregnant women should be careful of things like overheating, dehydration, dizziness, and fainting in the sauna. While it is not medically dangerous for a pregnant woman to be in the sauna, pregnant women must exercise caution to be safe. This most likely means not staying in the sauna for prolonged periods.
  • People who have 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. 

While these are all significant risk factors and guidelines, it’s most important for you to avoid staying in the sauna if you feel dizzy, overheated, or dehydrated. By leaving the sauna the moment you feel unwell, you will 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