Respiratory rate

How many breaths you take a minute while you sleep. Apple Watch estimates it overnight when you wear it to bed with sleep tracking on.

Respiratory rate is simply breaths per minute. Apple Watch estimates it while you sleep, which is handy: nobody breathes naturally when they know they're being counted.

You need sleep tracking with Apple Watch and Sleep Focus set up, and the watch on overnight. Apple's Vitals app takes about 7 nights to learn your typical range, and Apple says Vitals readings aren't meant for medical use.

Your sleeping rate is fairly steady from night to night, which is what makes a change worth noticing. In a wearable study of 10,000 adults, 9 in 10 nightly readings fell between about 12 and 19 breaths a minute. Apple notes that medicines, elevation, alcohol and illness can all shift overnight readings. In wearable studies, it has risen when people were unwell and after shorter sleep, and for many people it tends to be highest in the days before a period.

Pajdo compares each night with your usual from the previous four weeks and only mentions a rise that lasts at least two nights. With cycle awareness on, he uses the same days of your recent cycles once he has enough of them.

This is general wellness information, not medical advice. If a number worries you, or stays away from your usual for a while, talk to a doctor.

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