Inside the New Apple Watch Hypertension Alert Feature Powered by AI

Apple Watch Series 11 models will become available for purchase on September 19, 2025. The models come with an Apple Watch hypertension alert feature that notifies users about potential high blood pressure. According to Reuters, the tech giant used AI to power the hypertension feature as opposed to using a blood pressure monitor.

AI-Powered Data Analysis

According to the tech giant’s Vice President for Health Sumbul Ahmad Desai, the idea of the Apple AI blood pressure notification feature came from the application of AI models to existing sensor data. In November 2019, the tech company launched a heart and movement study to find patterns in its Watch’s heart sensor data that match regular blood pressure readings.

Apple used AI to analyze data from 100,000 people who participated in the study. The company’s privacy requirements only allow it to collect data through for large-scale studies. “One of the ironies here is we don’t get a lot of data,” Desai added. However, Apple said that data collected through this avenue still gives it “a sense of, what are some other signals that are worth pulling the thread on, those studies are incredibly powerful.”

After several layers of machine learning, the tech company developed an algorithm that it validated with a targeted study of 2,000 participants. Apple’s AI alert for high blood pressure feature will be available in Apple Watch models, starting with series 9 models. Apple unveiled Apple Watch Series 11 alongside iPhone 17 and AirPods Pro 3 on September 9, 2025 at its annual event.
Desai added that Apple has been working on ways to detect hypertension for years.

Approval by the FDA

On September 14, 2025, the U.S. Food and Drug Administration approved the hypertension alert feature, adding to the company’s growing portfolio of FDA-authorized health technologies, which includes Apple’s sleep apnea detection feature that got approval in 2024.
Apple’s hypertension detection feature works in the background during waking hours. It analyzes photoplethysmography (PPG) signals and changes in blood volume beneath the skin to detect patterns that suggest chronic high blood pressure.

Although it does not measure blood pressure directly, Apple’s health sensor detects hypertension and notifies users of potential risk. The feature also encourages such users to talk to a doctor and have readings taken using the conventional blood pressure measurement method.
Apple will be rolling out its hypertension notification feature in over 150 countries starting September 22, 2025.

Expert’s Take on Apple’s Hypertension Alert Feature

Cardiologists say the move could aid in the early detection of blood pressure and help in preventing related conditions like stroke, heart attacks and kidney disease.

“I’m glad to see Apple turning attention toward hypertension, the number one preventable cause of heart attack and stroke. Their approach automatically flags signals that suggest you may have high blood pressure and encourages you to check it out. That’s especially important because so many people remain undiagnosed,” Cardiologist and scientist Dr. Harlan Krumholz of Yale University and Yale New Haven Hospital said.

Globally, hypertension affects over 1 billion people. However, about 50% of those affected don’t know they have the condition. This is partly because the main standard of taking blood pressure readings is through the use of a sphygmomanometer, a device that most people only access at the doctor’s office.

Although the accuracy of Apple Watch AI blood pressure alerts remains high, with the specificity rate being more than 92%, experts emphasize that the new feature does not replace conventional investigation and diagnosis.

“This isn’t a one-stop solution, but it has the potential to help consumers take charge of their health and identify hypertension earlier. The caveat is that people shouldn’t rely on it exclusively; regular care remains essential,” Dr. Krumholz added.

American College of Cardiology’s Chief Innovation Officer Ami Bhatt said Apple should emphasize that its hypertension feature does not substitute professional diagnosis.

“There is also the risk of false reassurance, those who don’t get an alert may wrongly assume they don’t have hypertension,” Bhatt said