Can Sauna Help Lower High Blood Pressure?

There is now some fascinating research looking at sauna, heat therapy and cardiovascular health. Some of it suggests that regularly exposing the body to heat could potentially have beneficial effects on blood pressure and blood-vessel function.

But — and this is important — sauna isn't a replacement for blood-pressure medication, exercise, diet or medical care.

Let's look at what the research actually says.

First: what happens to your cardiovascular system in a sauna?

When you get hot, your body needs to get rid of that heat.

One of the main ways it does this is by sending more blood towards your skin.

Blood vessels near the surface of the body dilate — they get wider.

Your heart rate increases and your heart pumps more blood around the body. At the same time, the widening of the peripheral blood vessels can reduce vascular resistance.

In very simple terms:

Heat → blood vessels widen → blood flow increases → resistance to blood flow can decrease.

This is one reason researchers have become interested in whether repeatedly exposing the cardiovascular system to heat could produce longer-term adaptations.

What happens to blood pressure after a sauna?

A Finnish study examined 102 people with at least one cardiovascular risk factor before and after a single 30-minute sauna session.

The sauna was around 73°C.

Average blood pressure fell from approximately:

137/82 mmHg before sauna

to

130/75 mmHg immediately afterwards.

Systolic blood pressure remained lower during the 30-minute recovery period.

The researchers also found reductions in measures of arterial stiffness. [2,3]

That's interesting because stiff arteries are associated with ageing and cardiovascular disease.

But there's an important distinction here.

A reduction in blood pressure immediately after getting hot does not automatically mean sauna permanently lowers someone's blood pressure.

For that, we need to look at repeated exposure.

The Finnish study that really caught my attention

Researchers followed 1,621 Finnish men who did not have hypertension at the beginning of the study.

They followed them for a median of nearly 25 years.

The researchers compared how often the men used a sauna.

Compared with men sauna bathing once per week, those sauna bathing:

2–3 times per week had a lower observed risk of developing hypertension

and those sauna bathing

4–7 times per week had roughly half the risk.

After adjusting for numerous cardiovascular risk factors, the hazard ratio for developing hypertension in the 4–7 sauna sessions per week group was 0.53 compared with the once-weekly group. [4]

That's a pretty striking association.

However, this was an observational study.

It doesn't prove that sauna caused the reduction.

People who sauna frequently may differ in other ways from people who don't. The researchers adjusted for things including age, smoking, BMI, baseline blood pressure, alcohol, fitness and socioeconomic status, but observational research can never completely eliminate these differences.

So we can't say:

"Sauna prevents high blood pressure."

But we can reasonably say:

Frequent sauna bathing has been associated with a substantially lower risk of developing hypertension.

What happens when researchers actually prescribe sauna?

This is where things become more complicated — and more interesting.

An older clinical study followed 46 men with hypertension undergoing regular sauna therapy for three months.

Researchers reported significant reductions in resting systolic and diastolic blood pressure, as well as blood pressure during dynamic exercise. [5]

More recently, researchers conducted a randomised controlled trial looking at exercise combined with sauna.

Forty-seven relatively inactive adults with at least one cardiovascular risk factor were randomly allocated to exercise plus sauna, exercise alone, or a control group for eight weeks.

The sauna group completed a 15-minute sauna after exercise.

Adding sauna to exercise produced a greater reduction in systolic blood pressure than exercise alone, alongside improvements in cardiorespiratory fitness and cholesterol. [6]

That's particularly interesting because sauna shouldn't necessarily be thought of as an alternative to exercise.

The combination may be where things get really interesting.

But not every study finds a benefit

This is an important part of the story.

A 2025 randomised clinical trial studied 41 adults with untreated hypertension.

Participants completed either 30 heat-therapy sessions or 30 aerobic-exercise sessions over 8–10 weeks.

The researchers found that neither intervention significantly changed 24-hour ambulatory blood pressure in this particular study. [7]

So the evidence isn't as simple as:

"Get hot regularly and your hypertension disappears."

It doesn't.

A recent review of the field concluded that small clinical trials suggest heat therapy can lower blood pressure, but studies use different heating methods and protocols and results remain mixed. [8]

That's probably the fairest description of where the science currently stands.

Why might sauna help?

There are several possible mechanisms.

1. Blood vessel dilation

Heat causes blood vessels in the skin to widen, increasing peripheral circulation and reducing resistance to blood flow.

2. Arterial function

Experimental sauna research has demonstrated acute improvements in measures of arterial compliance and arterial stiffness. [2,3]

Healthy, flexible arteries are much better able to accommodate changes in blood flow than stiff arteries.

3. Repeated cardiovascular stress

Sauna isn't passive in the physiological sense.

Your heart rate increases, circulation changes dramatically and your thermoregulatory system works hard to keep your core temperature under control.

Repeated exposure to this controlled physiological stress may stimulate adaptations in the cardiovascular system.

It's a form of hormetic stress — a manageable short-term stress that potentially encourages the body to adapt.

4. Sauna may complement exercise

Exercise remains one of the best-supported lifestyle interventions for cardiovascular health and blood-pressure management.

But the exercise-plus-sauna RCT raises an interesting possibility: finishing exercise with heat exposure may provide an additional cardiovascular stimulus. [6]

We need considerably more research before we know exactly how important that effect is.

And then there's the bigger cardiovascular picture

The Finnish research doesn't stop at hypertension.

Another famous study followed 2,315 Finnish men for around 21 years.

More frequent sauna bathing was associated with progressively lower rates of sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease and death from all causes.

Men sauna bathing 4–7 times per week had substantially lower cardiovascular mortality than those sauna bathing once per week. [9]

Again, association does not prove causation.

But when you combine these long-term observations with experimental evidence showing changes in blood pressure, arterial stiffness and vascular function, there is a biologically plausible cardiovascular story emerging.

What about cold water if you have high blood pressure?

This is where I want to make an important distinction.

Heat and cold do very different things to your cardiovascular system.

Cold-water immersion activates a powerful cold-shock response.

Blood vessels constrict, the sympathetic nervous system activates and blood pressure can increase acutely.

A 2024 systematic review and meta-analysis found a small but significant increase in mean blood pressure following cold exposure in healthy individuals. [10]

So please don't assume that because sauna may be beneficial for cardiovascular health, jumping from a hot sauna straight into very cold water must be even better.

That simply hasn't been established.

If you have hypertension or cardiovascular disease, particularly if it isn't well controlled, cold-water immersion deserves additional caution.

Can you sauna if you already have high blood pressure?

For many people with stable, controlled hypertension, sauna appears to be well tolerated.

Reviews of the evidence have found sauna bathing generally safe in people with stable cardiovascular conditions, including controlled hypertension. [11,12]

But there's another side to this.

Heat dilates blood vessels, sweating reduces fluid volume and blood-pressure medication may amplify the fall in blood pressure.

That means some people can become dizzy or light-headed when standing up after a sauna.

A recent review also highlighted that we still need better safety evidence in older, frailer people and those taking certain cardiovascular medications. [13]

So if you have diagnosed hypertension, cardiovascular disease, take blood-pressure medication, experience dizziness/fainting, or aren't sure whether sauna is appropriate for you, speak to your GP or healthcare professional before starting regular sauna use.

And don't stop or reduce prescribed medication because you're taking saunas.

So… does sauna lower blood pressure?

The answer isn't a simple yes or no.

We know that:

A sauna session can produce acute changes in blood pressure and vascular function.

Frequent sauna bathing has been associated with a substantially lower long-term risk of developing hypertension.

Some intervention studies show reductions in blood pressure, including when sauna is combined with exercise.

But:

Not all randomised trials have found reductions in blood pressure.

And sauna has not been established as a replacement for conventional hypertension treatment.

That's where the evidence currently sits.

What I find exciting is that we're beginning to understand sauna as much more than sitting somewhere hot and relaxing.

Heat is a genuine physiological stimulus.

Your cardiovascular system responds to it.

And repeated exposure may encourage adaptations that are beneficial for vascular health.

With around three in every ten adults in England living with hypertension, that's an area of research worth paying attention to.

References

1. NHS England Digital. Health Survey for England 2024: Adults' health – prevalence of hypertension. 2026.

2. Laukkanen T, Kunutsor SK, Zaccardi F, et al. Acute effects of sauna bathing on cardiovascular function. Journal of Human Hypertension. 2018;32:129–138. doi: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. doi:10.1177/2047487317737629.

4. Zaccardi F, Laukkanen T, Willeit P, et al. Sauna bathing and incident hypertension: a prospective cohort study. American Journal of Hypertension. 2017;30(11):1120–1125. doi:10.1093/ajh/hpx102.

5. Winterfeld HJ, Siewert H, Strangfeld D, et al. The behaviour of central and peripheral haemodynamics in hypertensive patients treated with regular sauna therapy. 1994. PMID: 7801668.

6. Lee E, Kolunsarka I, Kostensalo J, et al. Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm, randomized controlled trial. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2022;323(3):R289–R299. doi:10.1152/ajpregu.00076.2022.

7. Kaiser BW, Comrada LN, Gibson BM, et al. No effect of either heat therapy or aerobic exercise training on blood pressure in adults with untreated hypertension: a randomized clinical trial. Journal of Applied Physiology. 2025;138(6):1600–1614. doi:10.1152/japplphysiol.00959.2024.

8. Novel exercise-based strategies for lowering blood pressure. International Journal of Sports Medicine. 2026. PMID: 42167335.

9. 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. doi:10.1001/jamainternmed.2014.8187.

10. Douzi W, et al. The effects of cold exposure (cold water immersion, whole- and partial-body cryostimulation) on cardiovascular and cardiac autonomic control responses in healthy individuals: a systematic review, meta-analysis and meta-regression. Journal of Thermal Biology. 2024;103857. doi:10.1016/j.jtherbio.2024.103857.

11. Hannuksela ML, Ellahham S. Benefits and risks of sauna bathing. American Journal of Medicine. 2001;110(2):118–126.

12. Kukkonen-Harjula K, Kauppinen K. Health effects and risks of sauna bathing. International Journal of Circumpolar Health. 2006. PMID: 16871826.

13. Acute blood pressure responses and safety considerations in heat therapy interventions: a narrative review. 2026. PMID: 41794190.