Negative effects of the sauna and other risks - what to watch out for?

Saunas are a traditional element of many cultures, which use them mainly for rest and relaxation. Besides its many health benefits, however, sauna bathing also carries numerous risks and negative effects. If you fall into any of the groups of the population below, we recommend that you consider carefully whether to use a sauna.

Negative effects of the sauna

The sauna is not recommended for men trying to conceive. Regular sauna visits reduce sperm motility, which fully recovers within half a year of stopping sauna use. Pregnancy and the sauna is a somewhat controversial topic; in theory a high body temperature can harm the foetus, but in practice we do not observe a higher incidence of affected children (in mothers who visit a sauna during pregnancy).

We also do not recommend the sauna for people under the influence of alcohol, with low blood pressure, people who are ill with a fever, with skin inflammations, after a myocardial infarction or with unstable angina pectoris (a form of ischaemic heart disease, presenting as a squeezing chest pain). The sauna should not be visited by athletes with an acute injury and swelling.^{1, 2}

During a sauna visit we lose a considerable amount of sweat on average, and with that comes the risk of dehydration and mineral imbalance. These begin to show as sudden exhaustion, discomfort, headache and muscle cramps. At that moment you must leave the sauna and hydrate. Dehydration and mineral imbalance can be prevented by proper nutrition and pre-sauna hydration.¹

In conclusion - to sauna or not?

The sauna, whether Finnish, infrared or steam, is generally a health-promoting tool. The health benefits of sauna bathing, such as prevention of diseases of the heart, blood vessels, brain and lungs, have already been reliably demonstrated many times. It can be said that regular, long-term sauna use is beneficial for almost everyone. There are, however, groups of the population for whom sauna bathing may do more harm than good in their specific stage of life or current state of health - which is why we recommend always taking your long-term and current state of health into account before using a sauna.

References:

1. Patrick, Rhonda P, and Teresa L Johnson. “Sauna use as a lifestyle practice to extend healthspan.” Experimental gerontology vol. 154 (2021): 111509. doi:10.1016/j.exger.2021.111509
2. Heathcote, Storme L et al. “Passive Heating: Reviewing Practical Heat Acclimation Strategies for Endurance Athletes.” Frontiers in physiology vol. 9 1851. 20 Dec. 2018, doi:10.3389/fphys.2018.01851