Apple is finally promising better sleep tracking for the Apple Watch as part of watchOS 9. The updated Sleep app will include a sleep stages feature. It will be able to detect REM and deep sleep stages and track them over time.
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You'll be able to view your sleep measurements along with other data, like heart rate and breathing rate, in the Health app on your iPhone. Those participating in the health research program will be able to submit their data to researchers in the Apple Heart and Movement Study.
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One of the most notable health features for watchOS 9 is that it will show how long a user has been in atrial fibrillation (AFib). It will let you know the time of day or week when AFib is most active.
You'll receive weekly alerts to help you get a better picture of your AFib frequency. The Health app will display a detailed history, along with information about lifestyle factors that may affect the condition, such as exercise , sleep, and alcohol consumption . You'll be able to download a PDF that includes your AFib history and lifestyle factors to share with your healthcare professionals .

The U.S. Food and Drug Administration approved Apple AFib history feature just last week. The feature is only available to users in the U.S. who are 22 years old and older and have been diagnosed with the condition.
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Additionally, Apple is introducing a Medications app for iPhone and Apple Watch to help users keep track of when to take medications . You can set custom schedules and reminders for each medication. Users in the US will be able to receive notifications if there are “potentially critical interactions” with medications they add to the Health app.
Information source: engadget.com
