Cardiologist warns of hidden hypertension but the new Apple Watch update can now alert you
Cardiologist Dr. Harlan Krumholz at Yale warns about hidden hypertension but a new software update for Apple Watch is making it easy to track hypertension.
Cardiologist and scientist Dr. Harlan Krumholz from Yale University and Yale New Haven Hospital has highlighted that “Hypertension is the leading preventable cause of heart attack and stroke, yet millions remain undiagnosed.” Apple is now addressing this silent risk with its newly FDA-cleared “Hypertension Notifications” feature for Apple Watch.
A new Apple Watch software feature called “Hypertension Notifications” can now alert users of hidden hypertension. Thankfully, you don’t need to buy the latest Apple Watch 11 for this hypertension alert feature. The ‘Hypertension Notifications’ feature will be available on Apple Watch Series 9 and newer, along with Apple Watch Ultra 2 and later models.
Apple has just received clearance from the US Food and Drug Administration (FDA) for its new hypertension notification feature on Apple Watch. The new hypertension alert will be available with the watchOS 26 update that will start rolling out from September 15 with watchOS 26 across more than 150 countries, including India.
“Making accurate detection easy and part of daily life can help people get care earlier and prevent avoidable harm,” Dr. Harlan Krumholz told Apple.
Why hypertension detection matters
According to experts and cardiologists world wide, hypertension, or chronic high blood pressure, is one of the most widespread yet underdiagnosed health conditions. According to the World Health Organization, around 1.3 billion adults globally live with it. It is a leading cause of heart attacks, strokes, and kidney failure, yet many people never realise they have it until serious complications occur.
The problem is that hypertension is often silent. It rarely shows symptoms, and a single doctor’s visit may not capture consistent high readings. By integrating passive monitoring into a device people already wear daily, Apple is attempting to bring awareness to a condition that is both preventable and treatable.
How Apple Watch detects signs of hypertension
The Apple Watch does not function as a blood pressure cuff and does not give specific systolic or diastolic readings. Instead, it uses its optical heart sensor, the same sensor that powers heart rate tracking, to monitor how your blood vessels respond to each heartbeat.
The watch continuously collects this data in the background. Using an advanced algorithm trained on large-scale studies involving over 100,000 participants, it analyses blood flow patterns to identify whether they match signs typically associated with hypertension.
This process is not instant. Instead, the watch reviews data over a 30-day period. If the algorithm detects consistent patterns suggesting high blood pressure, the user receives a notification. The approach is designed to minimise false alerts and only notify when repeated signs point towards a potential issue.
What happens when you get an alert
If your Apple Watch sends you a hypertension notification, it means the device has detected patterns that could indicate chronically elevated blood pressure. Apple recommends that users do not treat this as a diagnosis but as a prompt to take action.
The next step is to use a medically validated blood pressure monitor, such as a third-party cuff, to record readings at home for at least seven days. These results should then be shared with a healthcare provider. This approach aligns with the latest American Heart Association guidelines for diagnosing hypertension.
As per the official statement, Apple has built its reputation in health monitoring around “rigorous research and validation”. The hypertension notification system was trained using machine learning on massive data sets from clinical studies and population health research.
Its performance was then tested in a dedicated clinical trial involving over 2,000 participants, said Apple. While the feature does not catch every case of hypertension, Apple expects that with the scale of Apple Watch ownership, it could help over one million people with undiagnosed hypertension in the first year alone.
Hypertension alerts add to Apple’s growing suite of health-focused tools, which already include irregular rhythm notifications, ECG, blood oxygen monitoring, sleep tracking, and cycle tracking. While none of these features replace clinical diagnosis, they have steadily transformed the Apple Watch into a companion that nudges users towards healthier behaviours.
Apple’s latest step reflects a broader shift in consumer health technology: using wearable devices to bridge the gap between doctor’s visits and everyday life. With passive, long-term monitoring, people who would otherwise remain unaware of their risk now have an early warning system strapped to their wrist.
Should you rely on it?
Apple itself stresses that the hypertension alert is not a replacement for medical testing. Users should not ignore traditional check-ups or stop using validated blood pressure monitors. Instead, the feature is best seen as a safety net; one that can flag potential problems early, especially for people who rarely monitor their blood pressure otherwise.
