Blood pressure is one of the numbers people most hope a sauna will improve. It’s also easy to measure, so several infrared studies tracked it.
This page covers studies that measured blood pressure in infrared saunas specifically. It is general information, not medical advice. For infrared research in general, see the overview of infrared sauna benefits.
Short answer: blood pressure tends to drop right after an infrared session. A 2021 review of 31 hospital patients with high blood pressure found systolic pressure fell from 118.5 to 115.1 mm Hg after one Waon session, and from 124.2 to 108.8 mm Hg after repeated sessions in non-smokers. There was no control group, and heart rate rises sharply in a hot infrared cabin.
The 2021 Waon study
Kominami (2021) reviewed the records of 31 inpatients with high blood pressure, in Medicine. They were on standard treatment, including medication and lifestyle changes. Each had Waon therapy: 15 minutes in a far-infrared sauna at 60°C (140°F), then 30 minutes under a blanket, with fluids replaced based on weight lost.
| Group | Systolic (mm Hg) | Diastolic (mm Hg) |
|---|---|---|
| All, single session | 118.5 to 115.1 | 70.5 to 65.9 |
| All, repeated sessions | 122.3 to 116.9 (not significant) | 73.8 to 68.2 (not significant) |
| Non-smokers (11), repeated | 124.2 to 108.8 | 73.6 to 62.1 |
No adverse events such as low blood pressure or falls were reported. The authors concluded:
“WT is a simple method to reduce blood pressure in non-smoking patients with hypertension.”
Kominami K et al., Medicine, 2021
WT is their abbreviation for Waon therapy. The authors listed as limitations that the mechanism, the number of sessions needed, and how long the effect lasts are all unclear.
What happens in a hotter cabin
Jenkins (2026) had 12 healthy adults sit for 45 minutes in a far-infrared sauna at 65°C (149°F), in Experimental Physiology. Average heart rate rose from 74 to 153 bpm. Mean arterial pressure fell by 9 mm Hg right after, mostly through lower diastolic pressure. Plasma volume shrank by 11.6% as people sweated about 1.4 liters an hour.
Two of the 12 stopped early, at 40 and 43 minutes, because of extreme discomfort.
Limitations
The 2021 study was retrospective, had no control group, and only 11 people in its non-smoking group. Its patients were on blood pressure treatment in hospital. The 2026 study measured healthy adults in one session, not people with high blood pressure.
Here’s what the spec sheet won’t tell you. The heart rate in the 2026 study, 153 bpm, came from sitting still, so a hot cabin is not as passive as it feels.
My rule of thumb: read a post-sauna blood pressure dip as a short-term effect of heat, not as a treatment.
Bottom line: infrared sessions lowered blood pressure briefly in small studies, with a larger drop in one group of non-smokers, but no controlled trial has shown a lasting effect. For the broader evidence, see the benefits overview linked above.
Sources
- Kominami K, Takahiza E, Tabuchi M, Akino M, “Blood pressure-lowering effect of repeated Waon therapy in non-smokers with hypertension,” Medicine, 2021;100:e26266: europepmc.org
- Jenkins EJ et al., “Far-infrared sauna exposure at 65°C elevates core temperature,” Experimental Physiology, 2026: europepmc.org
- Cleveland Clinic, “6 Possible Benefits of Infrared Saunas,” October 9, 2026: health.clevelandclinic.org