Apple has unveiled a world-first feature that can alert users to deadly high blood pressure – and the company claims it could flag more than one million undiagnosed cases in its first year alone.
The Apple Watch Series 11, showcased at Apple’s annual September launch event in California, contains new software that uses its optical heart sensor to monitor blood vessel activity over time.
Advanced algorithms then analyse the readings and can detect signs of hypertension, a condition that affects an estimated 14 million adults in the UK.
According to NHS and charity figures, as many as five million Britons are living with the condition, also known as hypertension, but have not been diagnosed.
Globally, around 1.3 billion adults are affected.
High blood pressure, often dubbed the ‘silent killer,’ rarely has obvious symptoms but greatly increases the risk of heart attack, stroke and kidney failure.
Studies suggest it is responsible for around half of all heart attacks and strokes worldwide.
Announcing the new tool, Apple’s vice-president of health Dr Sumbul Desai said: ‘Using data from the optical heart sensor, the algorithm looks for chronic high blood pressure by analysing how your blood vessels respond to beats of the heart.
Apple has unveiled a feature that can alert people to deadly high blood pressure – and the company claims it could flag more than one million undiagnosed cases in its first year alone
The Apple Watch Series 11, showcased at Apple’s annual September launch event in California, contains software that uses its optical heart sensor to monitor blood vessel activity over time
‘The algorithm works in the background, reviewing data over 30-day periods, and will notify you if it identifies patterns of hypertension.’
Dr Desai said the novel approach was developed using ‘advanced machine learning methods and a series of studies totalling over 100,000 participants’.
While it will not detect all cases, Apple expects the watch will notify more than one million people with undiagnosed hypertension in the first year alone, ’empowering them to make life-saving behavioural changes or start treatment.’
The system is now awaiting clearance from the US Food and Drug Administration and the Medicines and Healthcare Products Regulatory Agency in the UK.
Apple says the tool will be rolled out in 150 countries, including the UK and Europe, later this month.
While launched on the new Series 11, the hypertension alerts will also be available on recent models – including Series 9 and later, and the Apple Watch Ultra 2 and later – via a software update to watchOS 26.
The move builds on a series of previous Apple Watch advances in heart health.
In 2018, the company introduced an electrocardiogram (ECG) app, allowing wearers to take a medical-grade ECG simply by resting a finger on the crown of the watch.
Previous updates have also added notifications for possible sleep apnoea – a night-time breathing disorder that is strongly linked to high blood pressure, heart disease and stroke
Advanced algorithms then analyse the readings and can detect signs of hypertension, a condition that affects an estimated 14 million adults in the UK
While it will not detect all cases, Apple expects the watch will notify more than one million people with undiagnosed hypertension in the first year alone
The sensor records the heart’s electrical signals and can identify irregular rhythms such as atrial fibrillation – a condition that significantly raises stroke risk but often goes undiagnosed.
Millions of people worldwide have since used the feature, and in many cases, it has led to early medical intervention.
Apple has also added irregular rhythm notifications, which monitor the wearer’s heartbeat in the background and alert them if signs of atrial fibrillation are detected.
More recently, the watch has offered low and high heart rate alerts, fall detection, blood oxygen monitoring and crash detection – features credited with saving lives in emergencies.
Previous updates have also added notifications for possible sleep apnoea – a night-time breathing disorder that, if left untreated, is strongly linked to high blood pressure, heart disease and stroke.
Hypertension, however, is an ambitious first for wearable tech, putting Apple ahead of its competitors.
Unlike atrial fibrillation, which produces distinct electrical patterns in the heart, high blood pressure has historically required an inflatable cuff to measure the force of blood against the artery walls.
By contrast, Apple’s new method uses subtle changes in the blood flow, picked up through light sensors in the back of the watch, to infer vascular stiffness and pressure trends over weeks.
Hypertension is thought to cause more than ten million deaths globally each year, and is the single biggest driver of cardiovascular disease.
More recently, the watch has offered low and high heart rate alerts, fall detection, blood oxygen monitoring and crash detection – features credited with saving lives in emergencies
High blood pressure has historically required an inflatable cuff to measure the force of blood against the artery walls
In Britain, it is estimated that one in three adults has high blood pressure, yet millions are unaware of it.
Current NHS advice is that adults over 40 should have their blood pressure checked at least every five years, and more often if they are at higher risk – a target many never meet.
Alongside the health innovation, the Series 11 also offers a thinner design, tougher glass with a ceramic coating, faster 5G connectivity and watchOS 26 with new watch faces and usability upgrades.
But it is the hypertension alert that has generated the most excitement – a first for any consumer device, and one that could reshape how millions of people monitor their heart health.
The Apple Watch Series 11 goes on sale later this month. Apple has not yet confirmed UK pricing.
In the US, the Series 11 starts at $399, with availability in stores from September 19.
