How a Pulse Oximeter Can Overestimate Blood Oxygen Levels

For a normal person, oxygen saturation of 97 to 99 is quite normal. Once we're down to 92, that could be a sign that there's something going wrong. The pulse oximeter tends to overestimate the true oxygen level in your blood in patients who have darkly pigmented skin. Mike Linsom-Colleagues published a study looking at just how often pulse oximeters gave inaccurate oxygen levels in black patients.