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Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallStart with compatibility and country availability before resetting anything. ECG works on Apple Watch Series 4 or later (except Apple Watch SE) and every Apple Watch Ultra model, paired with an iPhone XS or later, where Apple has approved the feature. If your watch qualifies, update both devices, complete ECG setup in Health, then retry with a dry watch, dry skin, a snug fit and your opposite-hand finger on the Digital Crown. Chest pain or other emergency symptoms require medical care, not troubleshooting.
The ECG app is a single-lead-style recording tool, not a replacement for a clinical 12-lead ECG. It cannot detect a heart attack, stroke, blood clot, high blood pressure, heart failure or every arrhythmia. See Apple’s instructions and limitations at Apple Support.
Check whether your Apple Watch supports ECG
A missing ECG app can mean the watch never supported the feature. Apple’s compatibility requirements are:
| Apple Watch | ECG support |
|---|---|
| Series 4 and later, excluding SE | Yes, where available |
| Apple Watch Ultra models | Yes, where available |
| Apple Watch SE | No |
| Series 1–3 | No |
- The paired iPhone must be an iPhone XS or later.
- ECG is not intended for people younger than 22.
- Apple says to use the latest available iOS and watchOS versions.
An SE or Series 1–3 cannot gain ECG through cleaning, an update or a reset. Owners of an unsupported model must use ordinary heart-rate features, obtain a clinical evaluation when needed, or consider a compatible replacement.
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![Apple Watch Series 11 [GPS 46mm] Smartwatch with Jet Black Aluminum Case with Black Sport Band - M/L. Sleep Score, Fitness Tracker, Health Monitoring, Always-On Display, Water Resistant](https://m.media-amazon.com/images/I/416RQ0rtsUL._SL160_.jpg)
- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
See Apple’s current device guidance at support.apple.com/en-us/120278 and the Apple Watch User Guide at support.apple.com/en-asia/guide/watch/apdea4c50a57/26/watchos/26.
Confirm ECG is available in your country or region
ECG is a regulated medical feature, so availability varies by country or region. Apple’s watchOS feature table lists supported locations, including the United States, but the list can differ from the place where your watch was purchased or where you now live: Apple watchOS feature availability.
Imported or refurbished watches, a move to another country, or a mismatch between purchase, iPhone and Apple Account regions can explain why ECG was present before but is no longer offered. Do not treat changing the iPhone region as a guaranteed or supported unlock; check Apple’s availability page instead. A regional restriction cannot be repaired with software.
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![Apple Watch Series 11 [GPS 42mm] Smartwatch with Rose Gold Aluminum Case with Light Blush Sport Band - S/M. Sleep Score, Fitness Tracker, Health Monitoring, Always-On Display, Water Resistant](https://m.media-amazon.com/images/I/31caPPnRysL._SL160_.jpg)
- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
Set up or reinstall the ECG app
Complete setup in Health
- Open Health on the iPhone.
- Tap Search, then Heart.
- Tap Electrocardiograms (ECG).
- Tap Set Up ECG App and complete the on-screen health and age information.
- Open the ECG app on the watch.
If there is no ECG section in Health, return to the compatibility, region and software checks. If the section exists but the watch app is missing, open Watch → My Watch → Heart and tap Install in the ECG section if Apple offers that button.
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Refresh the software relationship
- Install available iOS and watchOS updates.
- Restart both the iPhone and Apple Watch.
- Confirm the watch is paired with the intended iPhone.
- Check Health → Search → Heart → Electrocardiograms (ECG) for existing data.
Unpairing is a later step, not the first fix. It is disruptive, may require restoring a backup, and cannot overcome unsupported hardware or regional limits.
Take the recording correctly
The watch back and the Digital Crown form an electrical circuit through your body. Merely opening the app or hovering a finger near the crown is not enough.
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![Apple Watch SE 3 [GPS 40mm] Smartwatch with Starlight Aluminum Case with Starlight Sport Band - S/M. Fitness and Sleep Trackers, Heart Rate Monitor, Always-On Display, Water Resistant](https://m.media-amazon.com/images/I/31YiTby0pOL._SL160_.jpg)
- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
- A GREAT FITNESS TRACKER—SE 3 can track your workouts in a healthy number of ways—from running and strength training to simply achieving your 10K steps a day. With real-time metrics and Workout Buddy powered by Apple Intelligence from your nearby iPhone,* you’ll hit your goals like never before.
- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- WOMEN’S HEALTH INSIGHTS—SE 3 has advanced sensors that track your wrist temperature while you sleep. With this smartwatch, you can log your periods and symptoms, get period predictions, and get notified of cycle deviations.*
- GREAT BATTERY LIFE AND FASTER CHARGING—Enjoy a smartwatch with all-day, 18-hour battery life* from sunup to sundown. Then charge up to twice as fast as SE 2* and get up to 8 hours of battery in just 15 minutes.*
- In Watch → General → Watch Orientation, select the wrist on which you are wearing the watch.
- Wear the watch snugly, with its back flat against clean skin.
- Open the ECG app and rest your arm on a table or in your lap.
- Touch the Digital Crown with a finger from the opposite hand. Do not press or turn the crown.
- Remain still and keep contact for the full 30-second recording.
- Save symptoms if desired, then tap Done.
The ECG operating range is 32°F to 95°F (0°C to 35°C). Extreme heat or cold can make a reading unreliable. Remove an unusual case or accessory if it interferes with the crown, fit or skin contact.
Fix “poor recording” or “inconclusive” results
- Dry everything. Dry your wrist, the touching finger, the watch back and the Digital Crown. After swimming, showering, handwashing or heavy sweating, Apple says complete drying can take an hour or more. Water resistance does not make ECG contact work while the watch is wet.
- Improve contact. Tighten a loose fit enough for stable contact without discomfort. Keep the touching finger on the crown, not the band, case or another watch surface.
- Stop movement. Sit down, rest both arms, stop talking and typing, and avoid flexing the wrist for 30 seconds.
- Remove interference. Move away from plugged-in electronics, power adapters and questionable chargers before retrying.
- Retry when rested. Do not test immediately after exercise or while perspiring.
“Poor recording” means the signal quality was inadequate. “Inconclusive” means the strip could not be classified; causes include signal quality, movement, heart rate or another limitation. Apple notes that a small percentage of people may naturally produce a weaker signal because of physiological differences, including heart position. Repeated failures therefore do not automatically prove a defective watch.
If ECG worked before but stopped
- Reconfirm the model and current country or region.
- Update iOS and watchOS, then restart both devices.
- Check the selected wrist in Watch → General → Watch Orientation.
- Clean and completely dry the watch, crown, finger and wrist.
- Retry away from plugged-in electrical devices.
- In Watch → My Watch → Heart, reinstall ECG if an Install button appears.
- Check the feature version: on the watch, Settings → Heart → ECG; on iPhone, Health → Search → Heart → ECG → About. Apple explains regional version differences at support.apple.com/en-ca/102044.
If failure began after an impact, repair or liquid exposure, or occurs alongside other sensor problems, stop resetting the watch and arrange Apple evaluation.
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- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
- A GREAT FITNESS TRACKER—SE 3 can track your workouts in a healthy number of ways—from running and strength training to simply achieving your 10K steps a day. With real-time metrics and Workout Buddy powered by Apple Intelligence from your nearby iPhone,* you’ll hit your goals like never before.
- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- WOMEN’S HEALTH INSIGHTS—SE 3 has advanced sensors that track your wrist temperature while you sleep. With this smartwatch, you can log your periods and symptoms, get period predictions, and get notified of cycle deviations.*
- GREAT BATTERY LIFE AND FASTER CHARGING—Enjoy a smartwatch with all-day, 18-hour battery life* from sunup to sundown. Then charge up to twice as fast as SE 2* and get up to 8 hours of battery in just 15 minutes.*
What the ECG classifications mean
- Sinus rhythm: The recorded strip met the app’s criteria for a regular rhythm and did not show AFib according to that classification.
- AFib: The app detected a pattern that may be consistent with atrial fibrillation. It is not a definitive diagnosis.
- Inconclusive: The strip could not be classified, often because of signal quality, movement, heart rate or another limitation.
- Poor recording: The electrical signal was inadequate for useful classification.
These labels apply only to that recorded strip and do not rule out other conditions. Apple reports 98.3% sensitivity for AFib classification and 99.6% specificity for sinus-rhythm classification in classifiable recordings from a controlled study of approximately 600 subjects; those figures do not describe every real-world recording.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Find and share an ECG
- Open Health on iPhone.
- Tap Search → Heart → Electrocardiograms (ECG).
- Select the recording.
- Use the available share or export control to create a PDF for a healthcare professional.
A clinician can interpret the strip alongside your symptoms, history and other tests. A sinus-rhythm result does not prove that your heart is healthy, and an AFib result should not be self-diagnosed.
When to seek medical help immediately
Call emergency services for chest pain, pressure or tightness, severe shortness of breath, fainting or near-fainting, new severe weakness, confusion, or symptoms that feel like a heart attack. Apple explicitly says the ECG app cannot detect a heart attack. Do not delay care while trying another recording.
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Best Value
![Apple Watch Series 11 [GPS 42mm] Smartwatch with Jet Black Aluminum Case with Black Sport Band - S/M. Sleep Score, Fitness Tracker, Health Monitoring, Always-On Display, Water Resistant](https://m.media-amazon.com/images/I/41s72HIk5TL._SL160_.jpg)
- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
Contact a healthcare professional for an AFib result, repeated inconclusive readings, or symptoms that persist despite a seemingly normal strip. People with pacemakers or other implanted devices should follow their clinician’s advice and Apple’s device-specific medical guidance rather than relying on a generic troubleshooting rule.
When Apple service or replacement makes sense
Request service at Apple Watch repair and service when a compatible watch still fails after the checks above, especially after impact, liquid exposure, visible damage, abnormal Digital Crown behavior or failures in multiple sensors. Repair eligibility and cost depend on model, damage, warranty, AppleCare coverage and region.
Replacement is mainly relevant for an unsupported SE or Series 1–3, or a watch that Apple determines is uneconomical to repair. Compare current models at Apple’s buying page; do not buy a new watch before excluding setup, region, moisture, contact and service causes. AppleCare+ information is at apple.com/support/products/watch; it is not a retroactive fix for existing damage.
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