The most common way to measure oxygen saturation is with a pulse oximeter. Researchers are continuing to examine how skin color affects the accuracy of pulse oximetry readings. In one study, researchers found people who identified as Black had three times the frequency of undetected low blood oxygen compared with people who identified as white.
A procedure called arterial blood gas analysis is the most accurate way to measure blood oxygen level. With this procedure, blood is drawn from an artery in your wrist by a trained medical professional. Your blood is sent to a laboratory and results are usually available within a few minutes.
Doctors sometimes administer this test in emergency situations.