If Pillow does not display blood oxygen data please check the following:
Blood oxygen measurement depends on your Apple Watch’s hardware capabilities.
Pillow requires an Apple Watch Series 6 or newer
The ability to track blood oxygen levels is only available on Apple Watch Series 6 or later. If you are using an earlier model, Pillow cannot retrieve or display any data for Blood Oxygen Levels. Additionally, Apple has stated that "The ability to measure Blood Oxygen is no longer available on Apple Watch units sold by Apple in the United States on or after 18 January 2024." If your Apple Watch was purchased after this date within the United States, it may lack the capability to record blood oxygen levels.
Wear your Apple Watch during sleep
Pillow displays data for Blood Oxygen Levels for each sleep session. If you don't wear your Apple Watch during sleep, Pillow will not be able to retrieve any data for blood oxygen levels.
Check Apple Health Permissions
Pillow requires permission to access blood oxygen levels. To check if that permission is set up correctly:
Open the "Health App" on your iPhone.
Tap on your profile icon in the top right corner.
Go to "Privacy" > "Apps" > Pillow.
Turn ON "Blood Oxygen".
Enable blood oxygen levels tracking on the Apple Watch
Open the "Settings" app on your Apple Watch.
Go to "Blood Oxygen".
If your device and location meet the requirements, ensure the Apple Watch's system and firmware are up-to-date to access the required features.
Turn ON "Blood Oxygen Measurements", "In Sleep Focus", "In Cinema Mode".