If your Apple Watch supports it, you can record a single-lead electrocardiogram (ECG) right from your wrist in about 30 seconds, with no extra hardware required. This guide walks you through confirming your Watch is eligible, completing the one-time setup in the Health app, taking your first reading, understanding what the results actually mean, and exporting a PDF to share with your doctor.
What Is the ECG App?
The ECG app is a built-in feature on eligible Apple Watch models that records the electrical signals of your heartbeat by having you touch the Digital Crown for 30 seconds. Once the recording finishes, the app classifies your heart rhythm as Sinus Rhythm, Atrial Fibrillation (AFib), Inconclusive, or flags that your heart rate was too low or high to classify.
This is different from the always-on heart rate monitoring your Watch does in the background. The ECG app is something you open on purpose, say, if your heart feels like it’s racing or skipping, or your doctor has asked you to log occasional readings. Every reading syncs to the Health app on your paired iPhone, where you can review your history and export it as a PDF.
Important: The ECG app is not a diagnostic tool. Apple is explicit that it doesn’t replace a doctor’s evaluation or traditional diagnostic methods. It’s a way to capture and share a snapshot of your heart rhythm. Nothing in this guide should be treated as medical advice. If you have symptoms that concern you, contact a healthcare provider.
Before You Begin
Make sure you have:
- An eligible Apple Watch: Series 4 or later (Apple Watch SE, in any generation, does not have the ECG sensor and cannot run the app)
- A paired iPhone with the Health app (there’s no Android, Windows, or standalone Mac version of this feature)
- watchOS and iOS updated to a recent version on both devices
- You’re physically located in a country or region where Apple has enabled the ECG app; availability expands over time, so check the Health app itself or Apple’s support page if you’re unsure
- You’re 22 years or older, with your correct date of birth entered in your Health app profile (the app checks this before unlocking)
| Requirement | Details |
|---|---|
| Device | Apple Watch Series 4 or later (not SE) |
| OS version | watchOS and iOS updated in Settings > General > Software Update |
| Companion app | Health app on paired iPhone |
| Region | Country/region must have ECG enabled by Apple |
| Age | 22+, confirmed via Health app birthdate |
> You’ll need an Apple ID signed in on your iPhone, with the same Apple ID used to pair your Apple Watch.
Step-by-Step Guide
Step 1: Confirm Your Apple Watch and iPhone Are Up to Date
On your iPhone, go to Settings > General > Software Update and install anything available. Then open the Watch app on your iPhone, go to General > Software Update, and update watchOS if needed.
> Tip: You can also check your current iOS version at Settings > General > About. Apple periodically raises the minimum OS requirement for the ECG app, so keeping both devices current avoids most eligibility headaches.
Step 2: Confirm Your Watch Model Is Supported
Check your Apple Watch model on your iPhone at Settings > General > About, or on the back of the Watch case. The ECG app requires an eligible Series 4 or later Apple Watch, or an Apple Watch Ultra model. Apple Watch SE (any generation) does not include the ECG sensor. Confirm the current list on Apple’s ECG support page — do not treat a model roster in this article as complete. Apple Watch SE (any generation) does not include the ECG sensor and will never show this app, regardless of software version.
Step 3: Open the Health App and Find the Heart Category
On your iPhone, open the Health app and tap the Browse tab at the bottom. Tap Heart.
Step 4: Complete the One-Time ECG Setup
Inside the Heart category, tap Electrocardiogram (ECG). If you haven’t set it up before, you’ll see a setup screen. Tap Set Up ECG App and follow the prompts. This confirms your age, region, and Watch pairing, and enables the app icon on your Watch.
> Tip: This setup only needs to happen once. If you ever switch to a new iPhone or reset your Apple Watch, you’ll need to run through it again.
Step 5: Open the ECG App on Your Apple Watch
On your Apple Watch, press the Digital Crown to see your apps, then tap the ECG app icon (it looks like a heartbeat line). If this is your first time, the Watch will walk you through a brief explainer, so tap through it to reach the recording screen.
Step 6: Rest Your Arm and Start the Recording
Sit down, rest the arm wearing your Watch on a table or your lap, and make sure the band fits snugly against your wrist. Lightly rest the finger on your opposite hand on the Digital Crown, but don’t press it in. Tap Start on the Watch screen.
Step 7: Hold Still for 30 Seconds
Keep your finger resting on the Digital Crown, stay quiet, and avoid moving until the countdown finishes. The Watch will show a progress ring while it records.
Expected result: After 30 seconds, the recording stops automatically and a classification appears on screen.
Step 8: Review Your Result on the Watch
Your Apple Watch shows one of a few outcomes right away: Sinus Rhythm, Atrial Fibrillation, Inconclusive, Low Heart Rate, or High Heart Rate. You can add symptoms you were feeling at the time by tapping through the prompt that follows.
Step 9: Review Your Full History in the Health App
Every reading you take is saved automatically. On your iPhone, go back to Health > Browse > Heart > Electrocardiograms (ECG) to see a list of every past reading with its date and classification.
Exporting and Sharing a Reading
Once you have a reading you want to bring to a doctor, you can turn it into a shareable PDF.
On iPhone (iOS)
- In Health > Browse > Heart > Electrocardiograms (ECG), tap the specific reading you want to share.
- Scroll down and tap Export PDF.
- Your iPhone generates a standardized PDF report showing the waveform and classification.
- Tap the Share icon to send it by Mail, Messages, AirDrop, or save it to Files.
> Tip: If your doctor’s office uses a patient portal, saving the PDF to Files first lets you upload it directly from there instead of hunting through Mail attachments.
Sharing via Web
If you saved the exported PDF to iCloud Drive, you can retrieve it from any computer without needing your iPhone in hand. Sign in to iCloud.com in a browser, open iCloud Drive, and locate the PDF in whichever folder you saved it to (for example, your Health or Downloads folder). From there you can download it and attach it to an email or a web-based patient portal message to your doctor.
If you emailed the PDF to yourself instead, you can also open your webmail account in a browser on any computer and download the attachment from there, which is useful if you’re filling out paperwork at a doctor’s office kiosk or a shared computer.
Understanding Your Results
These plain-language explanations describe what each label means as a Watch classification, not a diagnosis:
- Sinus Rhythm: The recording showed a heartbeat pattern that’s considered typical and regular. This is the most common result for healthy readings.
- Atrial Fibrillation (AFib): The recording showed an irregular rhythm consistent with AFib, a condition where the heart’s upper chambers beat out of coordination with the lower chambers. This is a flag worth discussing with a doctor, not a confirmed diagnosis.
- Inconclusive: The Watch couldn’t confidently classify the rhythm, often due to movement, talking, or poor contact with the Digital Crown during the recording.
- Low Heart Rate / High Heart Rate: Your heart rate during that specific recording was outside the range the app can classify (generally below or above the typical resting range), so it couldn’t determine a rhythm result.
This is a separate feature from AFib History, which is an opt-in feature that estimates how often your heart has shown signs of AFib over recent weeks based on background monitoring, not a single on-demand recording. AFib History has its own eligibility requirements and a short risk-factor questionnaire in the Health app, found in the same Heart category.
Tips and Troubleshooting
The ECG app doesn’t appear on my Watch
Why it happens: Usually an unsupported model (any Apple Watch SE), outdated software, being in a region Apple hasn’t enabled yet, or never completing setup in the Health app.
Fix: Confirm your Watch is Series 4 or later, update both devices, and revisit Health > Browse > Heart > Electrocardiogram (ECG) on iPhone to complete setup.
My reading keeps coming back “Inconclusive”
Why it happens: Movement, talking, a loose watch band, or light/inconsistent contact with the Digital Crown during the recording.
Fix: Rest your arm on a table, make sure the band is snug, keep your finger resting lightly (not pressing) on the crown, and stay still and quiet for the full 30 seconds. Try again after sitting calmly for a few minutes.
I got “Low Heart Rate” or “High Heart Rate” instead of a rhythm result
Why it happens: Your heart rate at that exact moment was outside the range the app can classify; this isn’t a diagnosis on its own.
Fix: Wait until you’ve been sitting calmly for a few minutes, away from exercise, caffeine, or stress, then try again.
I can’t find an old reading to export
Why it happens: ECG recordings are stored in the Health app on iPhone. If a reading isn’t visible on the Watch, look there.
Fix: On iPhone, go to Health > Browse > Heart > Electrocardiograms (ECG), tap the reading, and use Export PDF.
Wrapping Up
You’ve now got the ECG app set up and know how to take a reading, make sense of the result, and hand a PDF to your doctor when it matters. It’s a genuinely handy feature for catching odd heart rhythm moments between checkups, but don’t treat any single result as a diagnosis; that’s still your doctor’s job.
| Step | Action | Applies To |
|---|---|---|
| 1-2 | Confirm Watch model and update software | iOS, watchOS |
| 3-4 | Complete one-time ECG setup | iOS (Health app) |
| 5-8 | Take and review a reading | watchOS |
| 9 | Review history | iOS |
| 10 | Export and share PDF | iOS, Web |