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The health benefits of sauna.

Sauna health benefits: what the research actually shows.

Regular sauna use is linked to lower blood pressure, fewer deaths from heart disease, fewer strokes and a lower risk of dementia. A single session lowers blood pressure for a while afterwards. We read the studies, checked every number and graded the evidence, so you can see what is well supported, what is promising and what is hype.

Updated · 17 min read

Generated sauna scene: a timber hut beside the sea, with swimmers walking to the water.

Sauna benefits at a glance

Regular sauna bathing is linked to lower blood pressure, fewer deaths from heart disease, fewer strokes and a lower risk of early death. Experiments in people show the short-term effects. The long-term results come mainly from one large Finnish study that followed people for decades. They are consistent, and the more often people bathed the lower their risk, but they can’t prove that sauna itself caused the difference.

  • 63% lowerrisk of sudden cardiac death in Finnish men who used a sauna 4–7 times a week, compared with once.5Association from a 21-year cohort
  • −7 mmHgaverage fall in systolic blood pressure after a single 30-minute session.2Short-term effect, 102 adults
  • 66% lowerdementia risk at 4–7 sessions a week. A larger cohort found a smaller effect.9,21Early evidence
  • 1 cohortsupplies almost all the long-term data: men and women in eastern Finland.The main limit on everything here
  • ModerateLower blood pressure. Falls after a single session, and frequent users develop high blood pressure less often.2,8
  • ModerateHeart health. Fewer sudden cardiac deaths and fatal heart disease in frequent users.5,6
  • ModerateFewer strokes. 61% lower risk at 4–7 sessions a week.7
  • ModerateHeart failure symptoms. Better walking distance and symptoms in trials of mild sauna.19
  • EarlyBrain health. Lower dementia risk in two Finnish cohorts.9,21
  • EarlySleep and mood. Most regular users say they sleep better; heat has eased depression in small trials.23,25
  • EarlyFewer colds. About half as many in one small trial.26
  • No evidenceDetox, weight loss, cancer prevention. See what sauna doesn’t seem to do.

Sauna is safe for most healthy adults, with a few clear exceptions, covered in who should be careful.

What happens in your body

A hot sauna works your heart without moving your muscles. Your skin heats quickly, blood moves to the surface to shed heat, your heart beats faster to keep up, and you start to sweat. In one experiment with 60 adults, 20 minutes at 80–90°C raised heart rate to an average of 143 beats a minute and core temperature to 38.6°C.1

What one session does to your bodyAverage measurements from two experiments: 60 adults after 20 minutes at 80–90°C, and 102 adults after 30 minutes at 73°C.
  • Skin40°Caverage skin temperature after 20 minutes at 80–90°C1
  • Core38.6°Crectal temperature after 20 minutes, up from about 37°C1
  • Heart rate143beats a minute on average after 20 minutes at 80–90°C1
  • Sweat0.46 kgof fluid lost on average in 20 minutes1
  • Blood pressure137 → 130systolic mmHg after 30 minutes at 73°C, still lower half an hour later2
  • Artery stiffness9.8 → 8.6pulse wave velocity in m/s after the same session3

Responses vary with temperature, humidity, time in the room and how used to sauna you are. In the 80–90°C study, 3 of 60 people fainted.

Afterwards, blood pressure drops below where it started. In 102 Finnish adults with at least one heart risk factor, a 30-minute session at 73°C lowered systolic pressure from 137 to 130 mmHg and diastolic from 82 to 75 mmHg, and arteries became less stiff.2,3 A German study found that blood pressure and heart rate during a 25-minute sauna at 93°C matched a light-to-moderate exercise test, then fell below baseline once people came out.4

Sauna and heart health, blood pressure and stroke

Most long-term evidence comes from the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD), which recruited men aged 42–60 in eastern Finland in the 1980s and followed them for over 20 years. In the best-known paper, 2,315 men were grouped by how often they used a sauna. Compared with once a week, men who used one 4–7 times a week had a 63% lower risk of sudden cardiac death (hazard ratio 0.37). The authors reported similar patterns for fatal heart disease, fatal cardiovascular disease and death from any cause.5

More sessions a week, lower riskRisk compared with people who used a sauna once a week or less. A hazard ratio of 1 means the same risk; 0.50 means half the rate. Further left is lower. Lines show the 95% confidence interval for the most frequent group.
  • 4 or more sessions a week
  • 2–3 a week
  • Same risk as once a week
  • Sudden cardiac death2,315 men, 21 years4 or more a week: 0.37 (0.18–0.75) · 2–3 a week: 0.785
  • Fatal cardiovascular disease1,688 men and women, 15 years4 or more a week: 0.23 (0.08–0.65) · 2–3 a week: 0.756
  • Stroke1,628 men and women, 15 years4 or more a week: 0.39 (0.18–0.84)7
  • High blood pressure1,621 men, 25 years4 or more a week: 0.53 (0.28–0.98) · 2–3 a week: 0.838
  • Dementia2,315 men, 21 years4 or more a week: 0.34 (0.16–0.71) · 2–3 a week: 0.789
  • Alzheimer’s disease2,315 men, 21 years4 or more a week: 0.35 (0.14–0.90) · 2–3 a week: 0.809
  • Respiratory diseaseCOPD, asthma or pneumonia; 1,935 men4 or more a week: 0.59 (0.37–0.94) · 2–3 a week: 0.7310
  • Psychotic disorders2,138 men, 25 years4 or more a week: 0.21 (0.08–0.52)11

All from the Kuopio Ischaemic Heart Disease (KIHD) cohort in eastern Finland, adjusted for age, blood pressure, cholesterol, smoking, diabetes, weight and other risk factors. Sauna habits were asked once, at the start. These are associations, not proof that sauna caused the difference.

Later KIHD papers found the same pattern elsewhere. In a group of 1,688 men and women, using a sauna 4–7 times a week was linked to a 77% lower risk of dying from cardiovascular disease.6 It was linked to a 61% lower risk of stroke7 and to about half the risk of developing high blood pressure.8

Time in the room mattered too. Men whose usual session lasted more than 19 minutes had about half the risk of sudden cardiac death of those who stayed under 11 minutes.5

Experiments back up the blood pressure link. A 2021 meta-analysis of heat therapy trials found that repeated heat lowered systolic blood pressure by about 4 mmHg on average and helped arteries widen.12 A 2020 meta-analysis of 16 sauna studies found blood pressure fell by about 5–6 mmHg in the half hour after a session, while heart rate rose by about 18 beats a minute.13 In one controlled trial, eight weeks of hot baths made sedentary young adults’ arteries work better and lowered their blood pressure, with no change in a comparison group.14 Outside Finland, a Japanese study of 30,076 adults found that people who took a hot bath almost every day had 28% less cardiovascular disease than those who bathed twice a week or less.15 That was tub bathing, not sauna, but it points the same way.

Sauna, fitness and living longer

Death rates in the 2015 Finnish study fell step by step with more sauna use. These are the raw numbers, before any adjustment for health or lifestyle.

Out of every 100 men, how many died during the studyUnadjusted death rates over about 21 years in the 2015 Finnish study, by how often the men used a sauna. Filled dots are deaths.

Once a week: 49 in 100 (601 men)

2–3 a week: 38 in 100 (1,513 men)

4–7 a week: 31 in 100 (201 men)

Crude rates: 49.1%, 37.8% and 30.8%5. Men who used saunas more often may also have been healthier in other ways; the study’s adjusted results are in the chart above.

Sauna doesn’t replace exercise. When researchers looked at fitness and sauna together, men who were both fit and frequent sauna users had the lowest risk: 40% lower death from any cause and 58% lower cardiovascular death than unfit men who used a sauna twice a week or less.16 The same held for sudden cardiac death.17 The two seem to add up.

Heart failure

In Japan, a mild dry sauna called Waon therapy (60°C for 15 minutes, then 30 minutes resting under a blanket) has been tested in people with chronic heart failure. In an early study, two weeks of daily sessions improved how well blood vessels widen, and 17 of 20 patients said their symptoms improved.18

The largest trial, WAON-CHF, randomised 149 people with advanced heart failure. Its main measure, a blood marker of heart strain called BNP, didn’t improve more than in the control group. Symptoms, the distance people could walk in six minutes and heart size on X-ray did improve, with no serious side effects.19 A 2018 meta-analysis also found benefits, based on small infrared sauna studies.20 If you have heart failure, discuss this with your cardiologist rather than trying it alone.

Sauna for the brain, mood and sleep

In the KIHD men, 4–7 sessions a week was linked to a 66% lower risk of dementia and 65% lower risk of Alzheimer’s disease.9 A separate Finnish study of 13,994 men and women, followed for 39 years, found a smaller effect: people who bathed 9–12 times a month had a 53% lower dementia risk over the first 20 years, but only 19% lower over the full 39.21 The link may be real but modest.

KIHD men who used a sauna most often also had fewer psychotic disorders, such as schizophrenia.11 A 2024 follow-up in the same cohort found the link held after allowing for fitness: men who bathed 3–7 times a week had about half the risk of those who bathed twice a week or less.22 It is still one cohort and needs repeating elsewhere.

For depression, the most interesting trial didn’t use a sauna. A single session of medical whole-body heating cut depression scores more than a sham treatment, and the difference lasted six weeks.23 A small Japanese trial of Waon therapy in mildly depressed patients improved appetite and physical complaints, with only a borderline effect on mood.24

For sleep, the evidence is self-reported. In the Global Sauna Survey of 482 regular users, 83.5% said sauna helped them sleep.25 The people who answered chose to take part and already liked sauna, so treat this as encouraging, not proven.

Sauna for colds and chest infections

In a 1990 German study of 50 adults, those who took regular saunas for six months had about half as many colds as the control group in the last three months, though their colds lasted just as long.26 In the KIHD cohort, men who used saunas four or more times a week had about 40% less respiratory disease (COPD, asthma or pneumonia) and less pneumonia.10,27

Sauna after a workout

Sauna after training is a form of heat acclimation. In a small crossover trial, six competitive runners who took a 30-minute sauna after training for three weeks ran 32% longer before exhaustion, and their blood plasma volume rose by 7%.28 That’s promising but tiny, and running longer to exhaustion doesn’t mean racing 32% faster: the authors estimated about a 2% gain in a time trial.

You may read that sauna boosts growth hormone sixteen-fold. That came from men sitting in an 80°C sauna for an hour, twice a day, for a week, and the effect faded after the third day.29 It says little about a normal session. Good evidence on muscle soreness and recovery is thin.

Sauna and your skin

Regular sauna users in a German study had a more stable skin barrier, better-hydrated skin and faster recovery after a test, compared with people who didn’t use saunas.30 It was a small comparison, not a trial.

What sauna doesn’t seem to do

Good research reports null results too. The KIHD team found no link between sauna and cancer risk.31 For blood clots the results were mixed: 2–3 sessions a week was linked to lower risk, but 4 or more wasn’t.32

  • No evidenceSweating out toxins. Your liver and kidneys clear waste. Sweat is mostly water and salt.
  • No evidenceWeight loss. You can lose half a kilo in a session, but it’s water, back as soon as you drink.
  • Overstated“11 minutes of cold and 57 of heat a week.” This comes from a Danish study of a few winter-swimming men. The numbers describe their habits; the paper recommends no dose.41
  • OverstatedHormone and longevity hacks. Big hormone spikes came from extreme, repeated exposure, and faded within days.29

How strong is the evidence?

A 2018 systematic review found 40 studies of regular dry sauna with 3,855 people. Only 13 were randomised trials, and most had fewer than 40 participants.33 The long-term results on heart disease, dementia and death come almost entirely from the KIHD cohort: mostly men, all in one region of Finland where sauna is part of daily life, with sauna habits recorded once at the start. They have not yet been repeated in another country or tested in a long randomised trial.

How strong is the evidence?
ClaimEvidenceWhat it rests on
Lower blood pressure, more flexible arteriesModerateCohort data, short experiments and a meta-analysis of heat therapy trials
Lower risk of heart disease and early deathModerateLong cohort studies with a clear dose–response, but mostly one Finnish cohort and no long trials
Better symptoms in heart failureModerateSmall trials and one multicentre randomised trial of Waon therapy
Lower risk of dementiaEarlyTwo Finnish cohorts; the effect was weaker over longer follow-up
Mood, stress and sleepEarlyA large survey and small trials of heat for depression
Fewer colds and chest infectionsEarlyOne small trial from 1990 and cohort data
Endurance performanceEarlyOne small trial in six runners
Skin barrierEarlyOne small comparison of regular users and non-users
Lower cancer riskNoneA Finnish cohort found no link
“Detox” through sweatNoneNo good evidence; your liver and kidneys clear waste
Lasting weight lossNoneThe weight lost is water, back when you drink

Our grades are a plain-English summary. “Moderate” means several kinds of study agree. “Early” means promising but small, few or self-reported. “None” means no good evidence, or a study that found no link.

Traditional, infrared or steam: which is best?

Almost all the long-term research is on traditional Finnish saunas: a wood or electric stove heating the air to 70–100°C, with low humidity that rises when water goes on the stones. Infrared cabins run cooler and heat the body directly with lamps. Most infrared research is the Japanese Waon work in heart patients, and a 2009 review found only limited evidence for infrared on blood pressure and heart failure.34 Steam rooms and hot baths have their own, smaller research base. If you want the benefits seen in studies, a traditional sauna at 70–90°C is the closest match.

Not all heat is the sameTypical air temperature (on a 0–110°C scale) and relative humidity (0–100%). Humid air feels hotter at the same temperature, because sweat can’t evaporate.
  • Air temperature
  • Humidity
  • Finnish saunawhere most research comes from70–100°C10–40%
  • Infrared cabinlamps heat the body more than the air45–60°C10–20%
  • Waon therapyJapanese clinical trials60°C10–20%
  • Steam roomhammam or steam bath40–50°C90–100%
  • Hot bathwater, not air38–41°CIn water

Typical ranges; individual rooms vary. Throwing water on the stones (löyly) briefly raises the humidity of a Finnish sauna.

How long and how often to use a sauna

There’s no proven best dose, but the studies point to a sensible routine. The strongest associations were at 4–7 sessions a week, with sessions of around 20 minutes. If you’re new, start with 5–10 minutes at a cooler temperature and build up. Daily sauna is normal in Finland and was the top group in most studies; there is no evidence that more than one or two sessions a day adds anything.

  1. Heat10–20 minutes at 70–90°C. Leave at once if you feel dizzy or unwell.
  2. CoolA shower, the sea or fresh air until you feel comfortable.
  3. RestSit for 10 minutes and drink water.
  4. RepeatTwo or three rounds, if you feel well. The studies’ best results came at 4–7 sessions a week.
  • Drink water before and after. You can lose around half a litre of sweat in 20 minutes.1
  • Don’t drink alcohol before or during a sauna.35
  • Stand up slowly. Blood pressure falls after a session, so dizziness is common, especially if you take blood pressure medicine.36
  • Leave if you feel faint, sick or have chest pain.

Who should be careful

Reviews find sauna is well tolerated by most healthy adults and children, and by most people with stable heart disease.35,36 Talk to your doctor first if any of these apply:

  • Unstable angina, a recent heart attack or severe aortic stenosis. These are the clearest reasons to avoid sauna.35
  • Low blood pressure, or medicines that lower it. The drop after a session can make you faint.36
  • Pregnancy. Large Finnish studies found no link between sauna and birth defects.39,40 Fever of 38°C or more in early pregnancy has been linked to defects, so ask your midwife or doctor, and keep sessions short and comfortable.40
  • Trying for a baby. In a small Italian study, two 15-minute sessions a week for three months lowered men’s sperm count and motility. Both fully recovered six months after they stopped.38
  • Children. Children tolerate sauna well, but should always be supervised and stay for shorter times.35

Alcohol is the big avoidable risk. Finland records fewer than 2 sauna deaths per 100,000 people a year, and half of the people who died had been drinking.37

How we wrote this page

We searched PubMed and other research databases for studies of sauna and health in people, and checked every number on this page against the published paper. Where a figure appeared only in a paper’s full text and we couldn’t check it, we left it out. We prefer randomised trials and large cohorts, report null results, and say where evidence is thin. We last reviewed the research on 21 October 2026 and will check for new studies every six months. Spotted something we missed or got wrong? Email us.

Olladay is booking software for saunas, and we’d like more people to use them. That’s a reason to be careful with claims, not to oversell them.

References

  1. Sohar E, Shoenfeld Y, Shapiro Y, Ohry A, Cabili S. Effects of exposure to Finnish sauna. Israel Journal of Medical Sciences. 1976;12(11):1275–1282. pubmed.ncbi.nlm.nih.gov/1017928/
  2. Laukkanen T, Kunutsor SK, Zaccardi F, et al. Acute effects of sauna bathing on cardiovascular function. Journal of Human Hypertension. 2018;32(2):129–138. 10.1038/s41371-017-0008-z
  3. Lee E, Laukkanen T, Kunutsor SK, et al. Sauna exposure leads to improved arterial compliance: findings from a non-randomised experimental study. European Journal of Preventive Cardiology. 2018;25(2):130–138. 10.1177/2047487317737629
  4. Ketelhut S, Ketelhut RG. The blood pressure and heart rate during sauna bath correspond to cardiac responses during submaximal dynamic exercise. Complementary Therapies in Medicine. 2019;44:218–222. 10.1016/j.ctim.2019.05.002
  5. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine. 2015;175(4):542–548. 10.1001/jamainternmed.2014.8187
  6. Laukkanen T, Kunutsor SK, Khan H, Willeit P, Zaccardi F, Laukkanen JA. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study. BMC Medicine. 2018;16:219. 10.1186/s12916-018-1198-0
  7. Kunutsor SK, Khan H, Zaccardi F, Laukkanen T, Willeit P, Laukkanen JA. Sauna bathing reduces the risk of stroke in Finnish men and women: a prospective cohort study. Neurology. 2018;90(22):e1937–e1944. 10.1212/WNL.0000000000005606
  8. Zaccardi F, Laukkanen T, Willeit P, Kunutsor SK, Kauhanen J, Laukkanen JA. Sauna bathing and incident hypertension: a prospective cohort study. American Journal of Hypertension. 2017;30(11):1120–1125. 10.1093/ajh/hpx102
  9. Laukkanen T, Kunutsor S, Kauhanen J, Laukkanen JA. Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men. Age and Ageing. 2017;46(2):245–249. 10.1093/ageing/afw212
  10. Kunutsor SK, Laukkanen T, Laukkanen JA. Sauna bathing reduces the risk of respiratory diseases: a long-term prospective cohort study. European Journal of Epidemiology. 2017;32(12):1107–1111. 10.1007/s10654-017-0311-6
  11. Laukkanen T, Laukkanen JA, Kunutsor SK. Sauna bathing and risk of psychotic disorders: a prospective cohort study. Medical Principles and Practice. 2018;27(6):562–569. 10.1159/000493392
  12. Pizzey FK, Smith EC, Ruediger SL, et al. The effect of heat therapy on blood pressure and peripheral vascular function: a systematic review and meta-analysis. Experimental Physiology. 2021;106(6):1317–1334. 10.1113/EP089424
  13. Li Z, Jiang W, Chen Y, et al. Acute and short-term efficacy of sauna treatment on cardiovascular function: a meta-analysis. European Journal of Cardiovascular Nursing. 2021;20(2):96–105. 10.1177/1474515120944584
  14. Brunt VE, Howard MJ, Francisco MA, Ely BR, Minson CT. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans. Journal of Physiology. 2016;594(18):5329–5342. 10.1113/JP272453
  15. Ukai T, Iso H, Yamagishi K, et al. Habitual tub bathing and risks of incident coronary heart disease and stroke. Heart. 2020;106(10):732–737. 10.1136/heartjnl-2019-315752
  16. Kunutsor SK, Khan H, Laukkanen T, Laukkanen JA. Joint associations of sauna bathing and cardiorespiratory fitness on cardiovascular and all-cause mortality risk: a long-term prospective cohort study. Annals of Medicine. 2018;50(2):139–146. 10.1080/07853890.2017.1387927
  17. Laukkanen JA, Laukkanen T, Khan H, Babar M, Kunutsor SK. Combined effect of sauna bathing and cardiorespiratory fitness on the risk of sudden cardiac deaths in Caucasian men: a long-term prospective cohort study. Progress in Cardiovascular Diseases. 2018;60(6):635–641. 10.1016/j.pcad.2018.03.005
  18. Kihara T, Biro S, Imamura M, et al. Repeated sauna treatment improves vascular endothelial and cardiac function in patients with chronic heart failure. Journal of the American College of Cardiology. 2002;39(5):754–759. 10.1016/S0735-1097(01)01824-1
  19. Tei C, Imamura T, Kinugawa K, et al. Waon therapy for managing chronic heart failure: results from a multicenter prospective randomized WAON-CHF study. Circulation Journal. 2016;80(4):827–834. 10.1253/circj.CJ-16-0051
  20. Källström M, Soveri I, Oldgren J, et al. Effects of sauna bath on heart failure: a systematic review and meta-analysis. Clinical Cardiology. 2018;41(11):1491–1501. 10.1002/clc.23077
  21. Knekt P, Järvinen R, Rissanen H, Heliövaara M, Aromaa A. Does sauna bathing protect against dementia? Preventive Medicine Reports. 2020;20:101221. 10.1016/j.pmedr.2020.101221
  22. Kunutsor SK, Kauhanen J, Laukkanen JA. Frequent sauna bathing and psychosis: interrelationship with cardiorespiratory fitness. Journal of Psychiatric Research. 2024;175:75–80. 10.1016/j.jpsychires.2024.04.044
  23. Janssen CW, Lowry CA, Mehl MR, et al. Whole-body hyperthermia for the treatment of major depressive disorder: a randomized clinical trial. JAMA Psychiatry. 2016;73(8):789–795. 10.1001/jamapsychiatry.2016.1031
  24. Masuda A, Nakazato M, Kihara T, Minagoe S, Tei C. Repeated thermal therapy diminishes appetite loss and subjective complaints in mildly depressed patients. Psychosomatic Medicine. 2005;67(4):643–647. 10.1097/01.psy.0000171812.67767.8f
  25. Hussain JN, Greaves RF, Cohen MM. A hot topic for health: results of the Global Sauna Survey. Complementary Therapies in Medicine. 2019;44:223–234. 10.1016/j.ctim.2019.03.012
  26. Ernst E, Pecho E, Wirz P, Saradeth T. Regular sauna bathing and the incidence of common colds. Annals of Medicine. 1990;22(4):225–227. 10.3109/07853899009148930
  27. Kunutsor SK, Laukkanen T, Laukkanen JA. Frequent sauna bathing may reduce the risk of pneumonia in middle-aged Caucasian men: the KIHD prospective cohort study. Respiratory Medicine. 2017;132:161–163. 10.1016/j.rmed.2017.10.018
  28. Scoon GSM, Hopkins WG, Mayhew S, Cotter JD. Effect of post-exercise sauna bathing on the endurance performance of competitive male runners. Journal of Science and Medicine in Sport. 2007;10(4):259–262. 10.1016/j.jsams.2006.06.009
  29. Leppäluoto J, Huttunen P, Hirvonen J, et al. Endocrine effects of repeated sauna bathing. Acta Physiologica Scandinavica. 1986;128(3):467–470. 10.1111/j.1748-1716.1986.tb08000.x
  30. Kowatzki D, Macholdt C, Krull K, et al. Effect of regular sauna on epidermal barrier function and stratum corneum water-holding capacity in vivo in humans: a controlled study. Dermatology. 2008;217(2):173–180. 10.1159/000137283
  31. Laukkanen JA, Laukkanen T, Kunutsor SK. Sauna bathing and risk of cancer: a prospective cohort study. European Journal of Cancer. 2019;121:184–191. 10.1016/j.ejca.2019.08.031
  32. Kunutsor SK, Mäkikallio TH, Khan H, Laukkanen T, Kauhanen J, Laukkanen JA. Sauna bathing reduces the risk of venous thromboembolism: a prospective cohort study. European Journal of Epidemiology. 2019;34(10):983–986. 10.1007/s10654-019-00544-z
  33. Hussain J, Cohen M. Clinical effects of regular dry sauna bathing: a systematic review. Evidence-Based Complementary and Alternative Medicine. 2018;2018:1857413. 10.1155/2018/1857413
  34. Beever R. Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence. Canadian Family Physician. 2009;55(7):691–696. pmc.ncbi.nlm.nih.gov/articles/PMC2718593/
  35. Hannuksela ML, Ellahham S. Benefits and risks of sauna bathing. American Journal of Medicine. 2001;110(2):118–126. 10.1016/S0002-9343(00)00671-9
  36. Kukkonen-Harjula K, Kauppinen K. Health effects and risks of sauna bathing. International Journal of Circumpolar Health. 2006;65(3):195–205. 10.3402/ijch.v65i3.18102
  37. Kenttämies A, Karkola K. Death in sauna. Journal of Forensic Sciences. 2008;53(3):724–729. 10.1111/j.1556-4029.2008.00703.x
  38. Garolla A, Torino M, Sartini B, et al. Seminal and molecular evidence that sauna exposure affects human spermatogenesis. Human Reproduction. 2013;28(4):877–885. 10.1093/humrep/det020
  39. Saxén L, Holmberg PC, Nurminen M, Kuosma E. Sauna and congenital defects. Teratology. 1982;25(3):309–313. 10.1002/tera.1420250307
  40. Tikkanen J, Heinonen OP. Maternal hyperthermia during early pregnancy and cardiovascular malformations in the offspring. European Journal of Epidemiology. 1991;7(6):628–635. 10.1007/BF00218673
  41. Søberg S, Löfgren J, Philipsen FE, et al. Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men. Cell Reports Medicine. 2021;2(10):100408. 10.1016/j.xcrm.2021.100408

Questions

What are the health benefits of sauna?

Regular sauna use is linked to lower blood pressure, fewer deaths from heart disease, fewer strokes, a lower risk of dementia and fewer chest infections. A single session lowers blood pressure and makes arteries less stiff for a while afterwards. Most long-term evidence comes from one Finnish cohort, so it shows association rather than proof.

Is it good to use a sauna every day?

For most healthy adults, yes. In Finnish studies, people who used a sauna 4–7 times a week had the lowest risk of heart disease, stroke and dementia. Keep sessions to around 20 minutes, drink water and skip alcohol.

Does sauna lower blood pressure?

Yes, for a while after each session: systolic pressure fell from 137 to 130 mmHg after 30 minutes at 73°C in one study. Over the long term, frequent sauna users developed high blood pressure about half as often. If you take blood pressure medicine, stand up slowly afterwards.

Is sauna good after a workout?

It can help endurance. In a small trial, runners who took a 30-minute sauna after training for three weeks ran 32% longer before exhaustion. There is little good evidence on muscle soreness or recovery.

Can a sauna help you sleep?

Probably, though the evidence is self-reported. In a survey of 482 regular sauna users, 83.5% said it helped them sleep.

Is sauna good for your heart?

Probably, for most people. Finnish men and women who used a sauna 4–7 times a week had much lower rates of fatal heart disease and stroke than once-a-week users over 15–21 years, and a single session lowers blood pressure for a while afterwards. The long-term data are associations from one Finnish cohort, so they suggest benefit rather than prove it.

How often should you use a sauna for health benefits?

The strongest associations in research were at 4–7 sessions a week, with sessions of about 20 minutes at 70–90°C. Two or three sessions a week was linked to smaller benefits. There is no proven best dose.

How long should you stay in a sauna?

Most studies used sessions of 10–30 minutes. In the Finnish cohort, men whose sessions lasted more than 19 minutes had about half the risk of sudden cardiac death of those who stayed under 11 minutes. Start shorter if you are new, and leave if you feel unwell.

Does sauna detox your body?

No. There is no good evidence that sweating in a sauna removes toxins in meaningful amounts. Your liver and kidneys clear waste.

Does sauna help you lose weight?

Not in a lasting way. You can lose around half a kilo of sweat in a session, but it is water and comes back when you drink.

Are infrared saunas as good as traditional saunas?

We don’t know. Almost all the long-term research is on traditional Finnish saunas at 70–100°C. Infrared research is mostly small Japanese trials in heart patients.

What temperature should a sauna be?

Most research used traditional saunas at 70–100°C with low humidity, and 70–90°C suits most people. Infrared cabins run cooler, at 45–60°C.

Is it safe to use a sauna when pregnant?

Large Finnish studies found no link between sauna and birth defects, but a fever-level body temperature in early pregnancy has been linked to defects. Ask your midwife or doctor, and keep sessions short and comfortable.

Who should not use a sauna?

People with unstable angina, a recent heart attack or severe aortic stenosis should avoid sauna. Anyone with a heart condition, low blood pressure, pregnancy or regular medication should ask a doctor first. Never drink alcohol before or during a sauna.

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