As a medical professional, I can tell you that a dangerously low oxygen saturation level, also known as hypoxemia, can be life-threatening if not addressed promptly. Oxygen saturation is a measure of the amount of oxygen carried by red blood cells in the blood, and it is typically measured by a pulse oximeter. Normal oxygen saturation levels are around 95 to 100 percent. When this level drops below 90 percent, it is generally considered low and may require medical attention. However, a level under 60 mm Hg is typically when supplemental oxygen is indicated as a medical intervention. read more >>

Hypoxemia is a below-normal level of oxygen in your blood, specifically in the arteries. ... Values under 60 mm Hg usually indicate the need for supplemental oxygen. Normal pulse oximeter readings usually range from 95 to 100 percent. Values under 90 percent are considered low.read more >>