An obstructive sleep apnea detection device including an optical engagement surface adapted to engage a user's skin； a light source adapted to emit light from the optical engagement surface； a photodetector adapted to detect light at the optical engagement surface and to generate a detected light signal； a position sensor adapted to determine patient sleeping position； a controller adapted to determine and record in memory blood oxygen saturation values computed from the detected light signal and user position information from the position sensor； and a housing supporting the optical engagement surface, the photodetector, the light source, the position sensor, and the controller.
