DeviceReviewed Sep 4, 2026

Ring

Oura Ring uses finger photoplethysmography, temperature and motion sensors to estimate sleep, activity and cardiovascular trends. Proprietary algorithms convert those signals into sleep and readiness scores.

At a glance

What it is, why people use it, the evidence, and what to know before trying it.

Device safety

Placement, electrical-device and medical precautions from the manual and reviewed sources.

Consumer sleep stages and readiness scores are estimates, not diagnoses. Fit, circulation, motion, illness and software changes can affect readings; persistent symptoms need clinical assessment regardless of a score.