What this measures
Your average number of breaths per minute while you were asleep, as your device estimated it.
How your device works it out
Most devices infer it from the way your pulse rises and falls with each breath, rather than measuring air moving. It is an estimate built from a heart-rate signal, which is why it is reported as an overnight average and not per breath.
What generally moves it
Altitude, room temperature, alcohol, how you slept, and where the device sat. It is usually steady from night to night, which is exactly why a change stands out against your own range.
Why Thriverence shows it
It is a stable input, so a shift away from your own usual band adds context to a Readiness score that has already moved for another reason.
What it is not
This does not detect any illness and it is not a medical measurement. A number above or below your usual range is not a sign of a condition and is never a reason to act on your own; if you are concerned about how you feel, the resources below are the route to a person.