A noninvasive method for recording central and obstructive apnea with bradycardia is described. A polygraphy was used to record impedance pneumography, heart rate, and air flow with a nasally positioned thermistor. Episodes of apnea both central and obstructive were measured. In addition, episodes of bradycardia were recorded and the relationship to respiratory events documented. The application of the method to 12 patients with 13 clinical diagnosis for observed episodes demonstrated that the clinical diagnoses were inaccurate in 10 of 13. The method improved diagnoses by detecting apnea, both central and obstructive, not detected by the use of routine monitoring.