Study Finds Smartwatch Hypertension Alerts Have Limitations

Alerts can detect likely cases of high blood pressure, but do not replace standard screening with an arm cuff, researchers say.

Published on Mar. 4, 2026

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A new study found that while the Apple Watch's hypertension notification feature can detect likely cases of high blood pressure, it does not replace the need for standard screening with a blood pressure cuff. The study found the feature has a positive predictive value of 69.1% and a negative predictive value of 79%, meaning an alert increases the probability of undiagnosed hypertension but the absence of an alert does not reliably rule it out.

Why it matters

With over 200 million Apple Watch users worldwide and nearly half of US adults having hypertension, the study's findings are important for understanding how to properly interpret and integrate these wearable technologies into clinical care and public health strategies.

The details

The study, published in JAMA, analyzed nationally representative blood pressure data and applied Apple's published performance metrics for the hypertension notification feature. For example, in people under 30, an alert boosts the chances of being diagnosed with hypertension from 14% to 47%, while the absence of an alert lowers the odds to 10%. In those over 60, an alert increases the probability from 45% to 81%, while no alert decreases it to 34%. The researchers recommend rigorous validation of the feature across diverse populations and settings, as well as clear communication to patients and clinicians about the tool's limitations.

  • The Apple Watch hypertension notification feature was FDA approved in 2025.

The players

Jordana Cohen, MD

Associate professor of medicine and epidemiology at the Perelman School of Medicine at University of Pennsylvania, Philadelphia, and lead author of the research letter published in JAMA.

Simon Walzel, PhD

Researcher at the Czech Technical University in Prague, Czech Republic, who was not involved in the study but provided commentary on the need for further validation of wearable hypertension technologies.

Apple

The company that developed the hypertension notification feature on the Apple Watch.

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What they’re saying

“We wanted to understand and amplify what an alert, or the absence of an alert, actually means at the population level given how many people are likely to impacted by this.”

— Jordana Cohen, MD, Associate professor of medicine and epidemiology (JAMA)

“Patients need to understand how to interpret alerts. Clinicians need to understand what an alert, or no alert, does and does not mean. Manufacturers and regulators should consider how performance varies across populations. And public health stakeholders should think carefully about how wearable technologies fit into existing screening strategies.”

— Jordana Cohen, MD, Associate professor of medicine and epidemiology (JAMA)

“This is a very timely and highly relevant analysis. I would advise clinicians and patients to treat this as a prompt, not a diagnostic tool. It is constantly available and can initiate follow-up, but confirmatory, cuff-based blood pressure measurement remains essential.”

— Simon Walzel, PhD, Researcher (JAMA)

What’s next

The study authors recommended rigorous validation of the hypertension alert feature across diverse populations and settings, as well as strategies to improve the accuracy of the device.

The takeaway

While wearable technologies like the Apple Watch's hypertension notification can increase awareness and prompt follow-up, they do not eliminate the need for routine, validated blood pressure screening with a traditional cuff. Clear communication about the limitations of these tools will be essential as they become more widely used.