Apple is at last promising better sleep tracking for Apple Watch as part of watchOS 9. The updated Sleep app will include a sleep stage function. It will be able to detect the REM, core and deep sleep stages and track those over time. 

You’ll be able to view your sleep metrics alongside other data, such as heart rate and respiratory rate, in the Health app on your iPhone. Those who participate in the health research program will be able to submit their sleep stage data to Apple Heart and Movement Study researchers.

One of the more notable health features for watchOS 9 is that it will show how long a wearer is in a state of atrial fibrillation (AFib). It will inform you of the time of day or week that AFib is most active.

You’ll receive weekly notifications to help you gain a better insight of your AFib frequency. The Health app will show a detailed history, along with information about lifestyle factors that may impact the condition, such as exercise, sleep and alcohol intake. You’ll be able to download a PDF that includes your AFib history and lifestyle factors to share with your healthcare professionals.

The US Food and Drug Administration granted Apple approval just last week for the AFib history feature. It’s only cleared for users in the US aged 22 and older who have been diagnosed with the condition.

In addition, Apple is introducing a Medications app for iPhone and Apple Watch to help users keep track of when to take their meds. You can set up custom schedules and reminders for each medication. Users in the US will be able to receive an alert if there are “potential critical interactions” with medications they add to the Health app.

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