what is considered low oxygen level

A low level of oxygen in the blood is called hypoxemia. A healthy level of oxygen in the arteries is about 75 to 100 millimeters of mercury (mm Hg), and hypoxemia is any value under 60 mm Hg. For most people, a normal pulse oximeter reading for oxygen saturation level is between 95% and 100% . Values under 90% are considered low. A resting oxygen saturation level between 95% and 100% is regarded as normal for a healthy person at sea level. However, oxygen saturation levels may be slightly lower at higher elevations. People should contact a healthcare provider if their oxygen saturation readings drop below 92%, as it may be a sign of hypoxia, a condition in which not enough oxygen reaches the body’s tissues. If blood oxygen saturation levels fall to 88% or lower, immediate medical attention is needed.