The ECG app on your Apple Watch is an electrocardiogram (ECG or EKG), similar to what you'd find in a doctor's office. You can use it to monitor certain aspects of your heart health. Here's what you need to know.

What the ECG App Does (and What It Doesn't Do)

With the ECG app, you can check:

• your exact heart rate at the moment. The optical sensor your watch uses throughout the day is more convenient and can track your heart rate while you work out, but it can be a bit finicky.
• whether you are currently experiencing a specific health condition called atrial fibrillation (AFib), where your heart beats with an irregular rhythm.

And that's it.

The ECG app can't detect heart attacks. If you experience any of the symptoms of one, don't open the ECG app: Call your doctor immediately. It also can't detect strokes, high blood pressure, high cholesterol, or even other kinds of irregular heart rhythms.

The ECG app is an undeniably cool feature. You can share the results with doctors, which suggests that it could be promising for telemedicine. However, the app is not a replacement for proper medical advice. It may be useful for detecting a single specific, intermittent condition, but it is not a general health check-up.

Related: How to Share an ECG from Your Apple Watch with Your Doctor

Which Apple Watch Models Have the ECG App?

The Apple Watch Series 4, Series 5, and Series 6 have the ECG app. The Apple Watch SE does not.

How Do I Use the ECG App?

Open the ECG app on your Apple Watch. Rest your hands on a table or on your legs, touch the Digital Crown with your finger, and follow the on-screen instructions to wait for 30 seconds.

At the end, you'll see the results. Possible results include:

• Sinus rhythm: Your heart is beating normally and your heart rate is between 50 and 100 bpm. However, if you feel ill, contact your doctor anyway.
• Atrial fibrillation (or AFib): This is the health condition that the ECG is designed to detect. Your heart is beating with an irregular rhythm. Contact your doctor.
• Low heart rate or high heart rate: Your heart rate is faster than 150 bpm (or 120 bpm with ECG app version 1) or slower than 50 bpm, so more specific results can't be given. Contact your doctor if you're concerned.
• Inconclusive: The results can't be determined. You might see this if you have a heart condition that the app can't detect, if you use a pacemaker, or (with ECG app version 1) if your heart rate is between 100 and 120 bpm and you do not have AFib. Contact your doctor if you're concerned.
• Poor recording: The results can't be determined. Make sure that your Apple Watch fits correctly and that your arms are resting on something steady, and try again.

Why Can't I Find the ECG App?

The ECG app is not available everywhere because of differing regulatory approval processes for medical devices. For example, the FDA approved the ECG app in the U.S. three years ago, while the Australian equivalent looks set to approve it by early 2021.

You can peruse a complete list of territories where the ECG app is available here.

If you are somewhere where the ECG app is available but still can't see it, you may need to set it up.

Update your Apple Watch and your iPhone to the latest versions of watchOS and iOS. Then, on your iPhone, open the "Health" app and tap "Set Up ECG app."

If you don't see that option, go to "Browse" > "Heart" > "Electrocardiograms (ECG)," then tap "Set Up ECG App" and follow the setup instructions.