You can now use your Apple Watch Series 4 to take an electrocardiogram (ECG test) and check for atrial fibrillation. Here's how to use these new features.

Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.

When Apple introduced the Apple Watch Series 4 a few months ago, we were excited to hear that it would include some next-level health features. Now, those features have officially launched and are available to Apple Watch users.

In addition to chatting with friends, streaming music, and tracking workouts, you can now use your Apple Watch to take an electrocardiogram (also known as an EKG or ECG test) to measure heart rhythm, as well as identify signs of atrial fibrillation (AFib). Both features go live today for Series 4 users as part of a free update to watchOS 5.1.2, and Series 1 through 4 users will get the irregular heart rate notifications with the update.

The new ECG app can generate an ECG similar to a single-lead electrocardiogram using electrodes in the back crystal and Digital Crown of the Series 4. To use, simply launch the ECG app and hold your finger against the Digital Crown, which will send a circuit of electrical signals across your heart to monitor for unusual heart rhythms.

After just 30 seconds, you'll get your reading: sinus rhythm (which means no unusual heart rhythms were detected), AFib, or inconclusive.

Credit: Apple

You should use this feature when you're experiencing strange symptoms (think rapid or skipped heartbeats); it's not recommended to take multiple ECG readings in a row or when you're feeling normal. The AFib feature runs in the background and will occasionally check for your heart rhythm; if five consecutive irregular heart rhythms are detected, you'll get a notification.

Credit: Apple

The company worked closely with the FDA to make sure the ECG and AFib tests had De Novo classification, meaning they're considered over-the-counter tools for consumers to monitor their health.

"Apple Watch has helped so many people around the world and we are humbled that it has become such an important part of our customers’ lives,” said Jeff Williams, Apple’s Chief Operating Officer in a statement. "With the release of these heart features, Apple Watch takes the next step in engaging and empowering people with more information about their health."

Credit: Manufacturer/Getty

Buy the Apple Watch Series 4:,,

As with all online health recommendations (this website included!), your results are not meant to officially diagnose you or replace regular doctor's appointments. But these new features could help you work with your doctor to gain a clearer picture of your overall health, especially because the results are automatically synced to the Health app on your iPhone. The stats can be quickly exported as a PDF that's formatted in a way physicians are used to seeing, making it even easier for them to interpret your results.

One Apple Watch user said the new health features alerted them to previously undiagnosed heart problems. After getting the AFib alert on their new Series 4, this Reddit user went to a cardiologist to have themselves tested, and was told that "this probably saved you."

"The role that technology plays in allowing patients to capture meaningful data about what’s happening with their heart, right when it’s happening, like the functionality of an on-demand ECG, could be significant in new clinical care models and shared decision-making between people and their health care providers," says American Heart Association CEO Nancy Brown in a statement to Apple.

Also important to keep in mind: These features are not recommended to those under 22 or to anyone who already knows they have atrial fibrillation. They also can't detect heart attacks; if you think you're experiencing possible heart attack symptoms like chest pain, shortness of breath, or tingling down your arms or legs, call your doctor right away.

This post was updated on 12/9/2018.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter