Apple’s latest health-related innovation is poised to have a very real-world effect. Regulatory approval in the United States for passive hypertension notifications is required, but Apple announced that feature would start next week in more than 150 countries and regions. The notifications will be accessible on Apple Watch 9 and later, as of Series 9 or Apple Watch Ultra 2 or better wearing watchOS 26.
A big public-health swing for the wrist
Hypertension continues to be one of the most underdiagnosed and undertreated diseases. The Centers for Disease Control and Prevention says nearly half of American adults have high blood pressure, and only about a quarter of them have it under control. Worldwide, the World Health Organization estimates that one in three adults has hypertension, around 1.3 billion people — many of whom do not know they have it and are at increased risk for heart attack, stroke and kidney failure.
That is why shifting screening signals onto a device that one wears all day could be significant. Identifying patterns early — before symptoms or complications occur — can set off timely home monitoring, changes in lifestyle or adjustments to medication. Apple projected during its product briefing that the feature could surface more than a million people with undiagnosed hypertension in the first year, a number that’s substantial at population scale even if the alerts don’t nail every case.
How the alerts work
The system leverages the watch’s optical heart sensor (photoplethysmography) to measure blood flow, and then applies a technology named photoplethysmographymetricsto quantify how blood vessels react to each heartbeat. Apple’s machine-learning tool finds long-term patterns common in the pulse wave features that it associates with consistently elevated blood pressure but not exact systolic/diastolic numbers. The algorithm is passive and takes a 30-day rolling average of data, sending an alert when it sees persistent indications of hypertension.
Importantly, it is not the same as a cuff. Consistent with American Heart Association recommendations for at-home monitoring, Apple suggests confirming any alert by taking blood pressure readings over seven days using a validated upper-arm cuff and sharing those with a clinician. That approach—passive, watch-based screening followed by cuff-based confirmation—is similar to how wearables already manage atrial fibrillation notifications.
Apple says the model was trained on data from several studies and validated in a clinical trial with over 2,000 participants. The company does not provide specific sensitivity and specificity numbers, but it admits that the system “won’t detect all cases of hypertension” and some users will receive alerts based on repeated follow-up despite having normal levels.
Compatibility, regions, and setup
Feature supported on Apple Watch Series 9 or later and Apple Watch Ultra 2 or later with watchOS 26. Apple says it will be available in more than 150 countries, including the United States and the European Union, upon approval from local regulators and language support. Like other Health attributes, users will need to consciously grant permission and notifications can be managed via the Health app.
Clinical caveats and what doctors will be looking for
Any cuffless approach carries caveats. Photoplethysmography is subject to the interference caused by factors such as skin perfusion, motion, tattoos and arrhythmias and can differ from one person to another. Clinicians will be not just monitoring accuracy but whether alerts lead to earlier diagnoses without swamping primary care with false alarms. Upper-arm readings done properly at home or in a clinic are still the gold standard.
But the promise is significant: passive, population-scale screening for a condition that frequently doesn’t have symptoms. For patients already managed for hypertension, recurrent alerts might initiate conversations about adherence, salt consumption, sleep quality or timing of medication — all areas where small changes really drive the needle on control rates.
How it fits in the wearable health world
Wearable companies have been trying to crack cuffless blood pressure for years. A few models offer cuff-calibrated spot checks and are limited in some markets. An FDA-cleared, passive notification system on a commercially available smartwatch is indicative of a transition from measurement to screening. It augments the wrist-based health tools that already exist on Apple Watch (including heart rhythm notifications, fall detection and an estimate of cardio fitness) by including a metric of high clinical consequence.
Bottom line for users
If you have a supported Apple Watch, upgrade to watchOS 26 when it debuts next week and enable hypertension notifications in the Health app. Treat an alert as a prompt, not a diagnosis: confirm it with a validated upper‑arm cuff for a week and share those readings with your clinician. For a disease that often goes undetected, a nudge of the wrist may be all it takes to push risk into silence or prompt someone to get the right care.