Sauna and risk of stroke

Sauna bathing has a long tradition, especially in the northern circumpolar countries, and it has become popular in Europe and the United States.^1,2 In Finland, with a population of 5.5 million, for example, 1 million saunas are in use. Most Finns take 1 or more sauna baths a week, starting in childhood. A number of reports about sauna bathing focus on its health benefits.^1–3 The public accept regular sauna bathing as a method of “hardening,” which means enhancing the body's resistance. Increased blood supply to the skin and mucosa improves regulation of body temperature, stabilization of the autonomic nervous system with decreased sympathetic activity, and the support of antioxidative protection potentials with improved defense against free radicals.³ The purported positive effects of sauna bathing for prevention of and therapy for cardiovascular diseases, such as coronary heart disease, and post myocardial infarction, congestive heart failure, and hypertension, remain unchallenged.¹ Positive effects are reported for glucose metabolism, whereby sauna bathing should work comparably to physical activity by sensitizing the tissue for the insulin-dependent glucose uptake.³ Through hyperthermia and elevated blood supply to the periphery of the body, diabetic complications such as macroangiopathy and microangiopathy can be counteracted.³ Regular sauna bathing may also lower serum cholesterol and its proportion in low-density lipoprotein.³ All these factors contribute to vascular health. Furthermore, in common disorders of the musculoskeletal system, sauna bathing contributes to pain relief and prevention of the transition of acute to chronic pain.³ In depression, chronic fatigue syndrome, and anorexia nervosa, sauna bathing may reduce symptoms.³ In addition, sauna bathing brings wellness, pleasure, and a certain type of hedonia; socializing can create camaraderie or friendship (figure).