The US FDA has given clearance for a new feature on the Apple Watch to allow users to monitor hypertension risk.

Available on the Apple Watch Series 9, 10, and 11 and Ultra 2 and 3 models, the new feature can alert users if signs of chronic high blood pressure are detected.

Hypertension is the leading modifiable risk factor for heart attacks, strokes, and kidney disease, impacting around 1.3 billion people globally. It’s known as the silent killer as it has no symptoms, and many people are unaware they are living with it.

The hypertension notifications use data from the optical heart sensor to analyse how a user’s blood vessels respond to the beats of the heart. The algorithm works passively in the background, reviewing data over 30-day periods. It will notify users if it detects consistent signs of hypertension so they can modify lifestyle behaviours.

The feature is expected to notify more than one million people with undiagnosed high blood pressure within the first year.

The feature was developed with advanced machine learning and training data from multiple studies, totalling more than 100,000 participants.

A new sleep score feature has also been added, which looks at overall sleep quality, taking into account duration, bedtime consistency, how often a person wakes up, and how much time is spent in each sleep stage, so users know what to prioritise to improve their sleep.