Heart rate app on Apple Watch
Heart rate app has stopped working. This is an app I need. What’s wrong?
Apple Watch Series 6, 9
Question marked as
It may be a hardware problem with the heart rate sensors. Do they turn green when you try to measure your heart rate? See the 'How Apple Watch measures your heart rate' section in:
Monitor your heart rate with Apple Watch - Apple Support
The first (and simplest) thing to try if something isn’t working right is to restart your Apple Watch and its paired iPhone. If necessary (device not responding), try a forced restart. Both methods can be found here:
How to restart your Apple Watch - Apple Support
Restart your iPhone - Apple Support
If that doesn't help, the next steps would be to unpair and pair your watch again and restore from the backup just created. This should result in no loss of data. It deletes all temp and corrupted files and re-indexes the file system.
Unpair and erase your Apple Watch - Apple Support
Set up your Apple Watch - Apple Support
Your best option may be to make an appointment at the Genius Bar in an Apple Store near your and let them look at it:
Genius Bar Reservation and Apple Support Options - Apple