Apple Watch can now alert you to possible hypertension — but how accurate is it?

If you own an Apple Watch, then you would know how useful it is when it comes to reminding you to stand, tracking your runs, or telling you to breathe when you’re stressed. And if that’s not enough, you’ll be glad to know that there’s now another reason to glance at your wrist. Earlier this month, Apple rolled out its new hypertension notifications feature in Singapore, a potentially life-saving update that could alert users to signs of chronic high blood pressure before it becomes a serious health risk.

This comes in handy, especially knowing that over one in three Singaporeans between 18 to 74 years old are affected by hypertension (or persistent high blood pressure), an increase from 35.5% in 2020 to 37.0% in 2022, according to the National Population Health Survey 2022.

But while the idea of your smartwatch flagging possible hypertension sounds revolutionary, the question remains: Can a wearable really know when something’s wrong with your heart?

What the hypertension notifications feature does

The new feature uses the optical heart sensor already built into the Apple Watch to analyse how your blood vessels respond to your heartbeat. To do so, you’ll have to remember to wear your Apple Watch for over a 30-day period, so it can detect irregular heartbeats and other consistent signs that may indicate hypertension. If the system notices something off, you’ll receive a notification, along with more details in the Health app on your iPhone. Upon checking your app, you’ll find valuable insights into your health, so you can take action early like adjusting your lifestyle habits or even seeking medical evaluation.

The new hypertension feature was actually designed and curated based on the data from more than 100,000 participants across multiple studies and clinically validated with over 2,000 people. But it’s also important to note that the Apple Watch does not detect all signs of hypertension, so it’s still recommended to visit your doctor to get your blood pressure checked regularly.

Another thing to note about the feature is that you can’t use it to detect hypertension during pregnancy and pre-eclampsia. On top of that, if you start to experience symptoms like chest pain, pressure, tightness, or think you have a heart attack, it’s important to note that this feature cannot detect heart attacks, and you’ll have to seek immediate medical attention.

Why detecting hypertension early matters

Hypertension affects roughly 1.3 billion adults worldwide and is a leading risk factor for heart attack, stroke, heart failure, and kidney disease. Yet it’s often called the “silent killer” because it usually has no noticeable symptoms.

You could feel perfectly fine and still have dangerously high blood pressure. Even if you go to a clinic for a routine check-up, your reading might appear normal that day. But if you track your cardiovascular signals continuously, with devices like the Apple Watch, subtle patterns could reveal early warning signs that might otherwise go unnoticed.

By analysing blood vessel responses over a 30-day period, the Apple Watch helps you see what a single snapshot at the doctor’s office might miss. If the feature detects consistent signs of hypertension, it gives you a nudge to be more proactive about your health — to get a proper blood pressure reading using a cuff, or to speak with a doctor about potential risks.

While it doesn’t replace regular medical check-ups, it’s a huge step in giving users more power and awareness. The ability to see trends over time allows you to make informed, preventative decisions — before hypertension progresses into something more serious.

How to turn on hypertension notifications on your Apple Watch

Here’s how you can enable the feature in just a few steps:

1. Make sure you an Apple Watch Series 9 or later or Apple Watch Ultra 2 or later, with the latest version of watchOS, as well as an iPhone 11 or later with the latest version of iOS. 
2. Tap your profile iconnull in the top corner.
3. Under Features, tap Health Checklist.
4. Tap Hypertension Notifications.
5. Confirm your age and if you’ve ever been diagnosed with hypertension, then tap Continue.
6. Tap Next to follow the onscreen prompts to find out how the notifications work.
7. Tap Done.

Once activated, the feature runs quietly in the background. You won’t get daily readings, but your watch will monitor vascular responses over time and alert you if it detects consistent signs of elevated blood pressure.

If you do receive a notification, Apple recommends confirming it using a blood pressure cuff and sharing your readings with a healthcare provider.

(Disclaimer: You must be 22 years or older, not pregnant and have not been diagnosed with hypertension.)

Beyond blood pressure: Tracking the quality of your sleep

Apple’s focus on holistic health doesn’t stop at your heart. The Apple Watch also provides comprehensive sleep tracking, giving users a clearer picture of their nightly rest — something many of us tend to take for granted.

Sleep plays a crucial role in regulating blood pressure, metabolism, and mental well-being, yet it’s often the first thing we compromise in our busy schedules. The Sleep Score on the Apple Watch evaluates how well you’re sleeping based on factors like bedtime consistency, sleep duration, and regularity of your sleep stages (light, deep, and REM sleep).

The data doesn’t just tell you how long you’ve slept, but it also shows you how well you’ve slept. Over time, these insights can help you spot patterns and make small but meaningful adjustments, like maintaining a consistent bedtime or improving your sleep environment.

When combined, features like sleep tracking and hypertension notifications form a powerful toolkit that allows users to take a more active, informed role in their health — not just when something goes wrong, but in preventing issues before they arise.