Some like it hot — the benefits of sauna and steam

Irish Examiner

02-05-2025

Bara Bada Bastu (Let's Just Sauna) is the Swedish entry in the Eurovision Song Contest this year and, according to the odds, it's the 'hot' favourite.
Saunas originated in Finland more than 2,000 years ago and were used for bathing, healing and socialising, among other benefits. Using heated hot stones to produce dry heat, they became a central part of Nordic culture.
Steam bathing, by contrast, dates back to the Roman Empire, when Romans used public baths daily while conducting business in a relaxed environment. Bathhouses or thermae were open to all and included steam rooms, changing areas, exercise rooms, swimming pools, cooling rooms, and massage spaces.
The main differences between saunas and steam rooms are the temperature and humidity levels. A traditional Finnish sauna is heated to a temperature between 40°C and 90°C with a humidity of around 10%. The temperature in a steam room is usually between 45°C and 50°C with 100% humidity.
Both saunas and steam rooms expose the body to hot air, but saunas stimulate sweating in an attempt to lower body temperature, whereas steam rooms reduce the body's ability to sweat. You may feel like you're sweating more in a steam room, but the droplets on your body are more likely to be condensed water from the humid air than perspiration.
It is difficult to say which is better for your health. There is more research on saunas than steam rooms, and not enough high-quality evidence directly comparing the two types to make any meaningful statements about health differences yet. However, research groups are studying this topic, so we should keep an eye on this space.
In the meantime, here's what we do know:
Congestion
A comprehensive review in the Cochrane Library (2017) found mixed results regarding the improvement of congestion associated with the use of steam rooms. Some participants had reduced symptoms of congestion, and others experienced discomfort while inhaling steam. Steam was found to improve the headaches associated with sinus symptoms but not other symptoms of chronic sinusitis.
Inflammation
The evidence for reducing inflammation is stronger for sauna bathing than steam bathing.
The evidence for reducing inflammation is stronger for sauna bathing than steam bathing. A study in the Annals of Medicine (2018) suggested that reduced markers for inflammation in regular sauna bathers could explain why sauna bathing is linked to lower levels of chronic disease, including type 2 diabetes, heart disease, strokes and cancer.
Stress
Sitting in a steam room can help you relax, but the science behind this is unclear. Some researchers suggest that heat helps release endorphins, the feel-good hormones that reduce stress and anxiety. Others suggest that steam room sessions help to reduce cortisol — the stress hormone.
Sitting in a steam room can help you relax, but the science behind this is unclear. Some researchers suggest that heat helps release endorphins, the feel-good hormones that reduce stress and anxiety. Others suggest that steam room sessions help to reduce cortisol — the stress hormone.
Skin health
Environmental exposure can predispose you to various toxins being trapped beneath your skin. Steam baths help to open pores and cleanse the skin. The warm condensation rinses away dirt and dead skin that can block pores and lead to breakouts, making skin clearer and improving the evenness of skin tone.
Research from the Arthritis Foundation indicates that heat can be beneficial in easing stiff joints and alleviating muscle pain in individuals with arthritis. The heat in saunas and steam rooms causes blood vessels to expand, allowing more oxygen and nutrients to flow to inflamed tissues. This can promote relaxation in both muscles and joints.
Cardiovascular health
Saunas originated in Finland more than 2,000 years ago and were used for bathing, healing and socialising, among other benefits. Using heated hot stones to produce dry heat, they became a central part of Nordic culture.
A recent study from Japan, published in Heart (2020), that followed more than 30,000 people over 20 years found that those who took hot baths nearly every day reduced their risk of cardiovascular disease by more than a quarter (28%) compared to those who took hot baths less than twice a week. Similarly, the risk of stroke was reduced by 26%.
In 2018, a review in Mayo Clinical Proceedings linked frequent sauna bathing (four to seven times a week) to lower blood pressure and decreased risk of cardiovascular disease, including sudden cardiac death and stroke.
Both steam rooms and saunas offer potential health benefits, but there are a few things to consider. Staying in a steam room for more than 15 minutes can lead to dehydration and fainting is not uncommon in saunas. Experts advise sipping water while in a sauna or immediately afterwards.
A steam room can be a host to other people's germs, so avoid it if you are pregnant, immunocompromised or recovering from surgery.
I enjoy taking saunas with a view of the Atlantic Ocean. However, the cost and Irish weather preclude me from doing this several times a week year-round, as is the case in Nordic countries.
I often use the sauna for 15 to 20 minutes after a swim. In the summer, I enjoy using an outdoor sauna for an hour, interspersed with two or three dips in the ocean.
The available evidence suggests that it is beneficial for my cardiovascular health and reduces the risk of chronic disease.
My experience is that it leads to an immediate sense of wellbeing, banishes anxieties, eases aches and pains in muscles and joints and sets me up for a long and uninterrupted sleep at the end of the day.
For me, saunas are definitely a 'hot' favourite.
Dr Catherine Conlon is a public health doctor
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