How Sleep Apnea Detection Works on Apple Watch Series 10, Series 9, and Apple Watch Ultra

Apple is bringing sleep apnea detection to the Apple Watch Series 10, Apple Watch Ultra 2, and Apple Watch Series 9. Given that sleep apnea is a breathing disorder, it’s easy to assume it would require a blood oxygen sensor, but Apple actually uses a completely different method to detect it.

Breathing Disorders, as the new Apple Watch indicator is called, uses a built-in accelerometer to detect small wrist movements that are associated with disruptions to normal breathing patterns during sleep.

Apple Watch collects 30 days of data and then analyzes it, alerting users if there are consistent signs of moderate to severe sleep apnea. Users will see elevated or non-elevated readings in the Breathing Disorders section of the Health app, and the data can be shared with a doctor to inform next steps in diagnosing and treating sleep apnea.

While aggregating data to detect sleep apnea requires 30 days of information, users can see a general overview of their nightly breathing disorders in the Health app to assess restful sleep. Breathing patterns can be disrupted by alcohol, medications, and sleep position.

With sleep apnea, breathing stops temporarily during sleep, preventing the body from getting enough oxygen and often waking the person up. It can be a difficult condition to diagnose because it occurs during sleep, and Apple says it’s estimated that more than 1 billion people worldwide are affected.

Apple says its sleep apnea notification algorithm was created using advanced machine learning and an extensive data set of clinical-grade sleep apnea tests, then validated in a clinical trial. Every participant identified by the algorithm had at least mild sleep apnea.

Apple expects the sleep apnea device to receive authorization for sale from the FDA and other global health authorities in the near future. It will be available in more than 150 countries this month.