Apple announced one of its most long-awaited new features for the Apple Watch series at its recent iPhone 17 family launch event: Apple Watch blood pressure alerts.
Apple Watch owners will be able to receive alerts when their smartwatches believe they’ve found signs of high blood pressure, or hypertension.
The best bit is they don’t need the very latest hardware for this to work. Apple’s newest watches are the Apple Watch Series 11, Ultra 3 and SE 3, but models as far back as the Watch Series 9 get the invite.
One important part to take on-board about Apple’s hypertension feature is it is not a replacement for a blood pressure cuff. It does not provide actual, concrete readings. Instead it looks for patterns in blood flow that indicate possible hypertension.
Should one of these alerts pop up, Apple suggests you begin logging your blood pressure using a traditional blood pressure cuff rather than an Apple Watch.
“It is recommended that they log their blood pressure for seven days using a third-party blood pressure cuff and share the results with their [healthcare]
provider at their next visit,” says Apple.
How Apple Watch Blood Pressure Readings Work
Much as the Samsung Galaxy Watch series is not a standalone replacement for conventional blood pressure hardware, the Apple Watch eventually needs to be used in concert with those methods.
However, Apple has managed to flip the equation around. Where Samsung’s method begins with a calibration session using a blood pressure cuff, establishing a baseline, the Apple Watch can notice changes without initial calibration.
Both watches make their blood pressure analysis using the same optical heart rate reader hardware on the rear of the watch, the same used to determine heart rate day-to-day. And thanks to the increased depth of information required here, versus a simple bpm reading, Apple analyzes data over an extended period before sending out an alert.
“The algorithm works passively in the background reviewing data over 30-day periods, and will notify users if it detects consistent signs of hypertension,” Apple says.
Samsung employs a somewhat comparable method, and the use of optical sensors to judge hypertension has been the subject of numerous studies.
The Key Win of Apple Watch Blood Pressure Readings
While it has similarities with the Samsung Galaxy Watch, Apple’s approach has several compelling strands that could provide significant advantages for the wider Apple Watch user base.
First, high blood pressure alerts are designed for folks who have not already been diagnosed with hypertension. Next, the lack of initial calibration stage dramatically lowers the barrier to entry, letting Apple rely on passive readings. And the years Apple has put into working on the accuracy of its HR sensors should not be undervalued.
Apple’s own estimates for its usefulness are not slight either. “The feature is expected to notify over 1 million people with undiagnosed hypertension within the first year,” reads Apple’s blog on the feature.
This is a natural follow-up to the irregular heart rhythms notifications the Apple Watch series has had since 2018.
Writing about wearables, you often come across stories of people who claim their Apple Watch saved their life, leading to (in some cases) a diagnosis of atrial fibrillation. In all the cases I can remember, this stemmed from passive readings based on optical heart rate reader information rather than the electrocardiogram feature introduced in the Apple Watch Series.
It’s the best feature of Apple’s blood pressure alerts: they require no real effort on behalf of the wearer, which is virtually essential to make the feature as beneficial as this has the potential to be.
