Sauna and blood pressure: is it safe?
By the Find My Sauna team·
Updated ·
7 min read
If you have high blood pressure, or take tablets for it, it's sensible to wonder what a hot room does to it. The reassuring news is that blood pressure usually falls a little during and after a sauna. That same drop is also the reason to take a few simple precautions.
The short answer
For most people a sauna is safe with high blood pressure that's under control. The heat widens your blood vessels, so blood pressure usually drops a little for a while afterwards. Over the long term, a Finnish study linked using a sauna 4–7 times a week to about half the risk of developing high blood pressure. If your blood pressure is very high or poorly controlled, or you take medicine for it, ask your doctor first, stand up slowly and never drink alcohol before or during a sauna.
What happens to blood pressure in a sauna
When you sit in a hot sauna, the blood vessels in your skin open wide to let heat escape. With more room in the system, the pressure inside the vessels tends to fall. Your heart speeds up to keep blood moving, and you start to lose fluid as sweat.
The clearest measurements come from a 2018 Finnish study in the Journal of Human Hypertension. In it, 102 adults with at least one heart risk factor sat in a sauna at 73 °C (163 °F) for 30 minutes. Their average blood pressure went from 137/82 before the session to 130/75 straight after. Systolic pressure, the top number, was still lower after half an hour of rest.
That's an average. Individual readings move around, and blood pressure can rise briefly at moments of effort or sudden cold. But for most people, the overall direction is down.
The long-term link
One session tells you little about the years ahead. For that, the evidence comes from the Kuopio study in eastern Finland. In a 2017 paper in the American Journal of Hypertension, researchers looked at 1,621 men aged 42 to 60 who did not have high blood pressure at the start. Over a median of almost 25 years, 251 of them developed it. Compared with men who used the sauna once a week:
- 4–7 times a week was linked to a 46% lower risk of developing high blood pressure. After further adjustment for fitness, alcohol, income and family history, the figure was 47%.
- 2–3 times a week was linked to a 24% lower risk, but this result was not statistically clear and could have been chance.
It's one study, of Finnish men, and it's observational. It shows that frequent sauna users were less likely to develop high blood pressure, not that the sauna prevented it. The authors themselves called for more research. Our guide to sauna and heart health covers what the same study found about the heart.
Why it might work
The leading idea is that regular heat trains your blood vessels. In the 2018 study, the arteries were measurably less stiff straight after the sauna. Stiff arteries and high blood pressure tend to go together, so anything that keeps arteries flexible could help in the long run. A 2001 review in the American Journal of Medicine also noted that some small studies suggest long-term sauna bathing may help lower blood pressure in people who already have it, though it said more data were needed.
None of this has been tested in a long randomised trial. It's a plausible explanation, not a proven one.
If you have high blood pressure
If your blood pressure is under control and you otherwise feel well, a sauna is generally fine. It isn't a treatment, though, and it's no reason to change your medicine.
If your blood pressure is very high or poorly controlled, or you've had a heart attack or stroke, talk to your doctor before you go. The 2001 review advised against saunas altogether for people with unstable angina, a recent heart attack or severe aortic stenosis.
Blood pressure medicine and the sauna
Blood pressure tablets lower your pressure. The heat lowers it a bit more, and sweating takes fluid out of your blood. Put these together and your blood pressure can drop further than usual, especially when you stand up. That's when people feel dizzy, see stars or faint.
This doesn't mean you can't use a sauna. It means you should:
- start with shorter rounds, 5–10 minutes, on a lower bench where it's cooler
- drink water before and after
- tell your doctor or pharmacist you use a sauna, and ask whether any of your medicines need extra care
- never stop or change your medicine to fit around the sauna
Stand up slowly
The riskiest moment is often the end of a round. Your blood vessels are wide open, a lot of blood is sitting in your legs, and you stand up quickly from a hot bench. Blood pressure can fall for a few seconds before your body catches up.
- Move down to the lowest bench for the last minute.
- Sit up, move your feet and legs, then stand slowly.
- Hold the rail as you step down and out.
- If you feel lightheaded, sit or lie down straight away.
Alcohol and the sauna
Alcohol and sauna heat are a bad mix. The 2001 review found that drinking alcohol during sauna bathing raises the risk of low blood pressure, an irregular heartbeat and sudden death. In Finland, alcohol is a common factor in the rare deaths that happen in saunas. Keep drinks for well after you've cooled down and rehydrated, or skip them.
Cold plunges and blood pressure
Cold water does the opposite of heat. Blood vessels in the skin clamp shut, and heart rate and blood pressure jump in the first minute. Healthy people handle this well, but if you have high blood pressure or heart disease it's a real strain. Ask your doctor before you try a plunge or ice bath, and in the meantime cool off with a lukewarm or cool shower. The cold plunge guide explains the cold shock response, and how long to stay in a sauna covers round lengths.
Who should be careful
- People with very high or poorly controlled blood pressure.
- Anyone with unstable angina, a recent heart attack or stroke, or severe aortic stenosis.
- People who often feel dizzy on standing, or who have fainted before.
- Anyone on blood pressure medicine, especially if it's new or the dose has just changed.
- Pregnant women, who should check with their midwife or doctor.
Leave the sauna if you feel dizzy, sick, confused or have chest pain.
This guide is general information, not medical advice.
Where to find a sauna
Find My Sauna lists 2,616 places with a Finnish-style sauna. These cities have the most:
Frequently asked questions
Is a sauna safe if you have high blood pressure?
For most people whose blood pressure is under control, yes. If it is very high or poorly controlled, or you have heart disease, ask your doctor first.
Does a sauna raise or lower blood pressure?
It usually lowers it. In a 2018 study, average blood pressure fell from 137/82 to 130/75 after a 30-minute session. It can rise briefly with sudden cold or effort.
Can I use a sauna if I take blood pressure tablets?
Usually, but you are more likely to feel faint when you stand up. Start with short rounds, drink water, get up slowly and tell your doctor you use a sauna.
Can a sauna lower blood pressure long term?
A Finnish study linked using a sauna 4–7 times a week to a lower risk of developing high blood pressure. It is not a treatment and it does not replace medicine.
Why do I feel dizzy after a sauna?
Your blood vessels are wide open and blood pressure is lower, so standing up quickly can leave your brain short of blood for a moment. Sit down, then get up slowly.
