Oxygen saturation refers to the level of oxygen found in a person's blood, as indicated by the Mayo Clinic's definition of hypoxemia. A healthy person's blood is maintained through a certain oxygen saturation range to adequately deliver oxygen to cells and tissues.
Blood oxygen saturation that is too low results in hypoxemia, causing the person to experience symptoms including shortness of breath, states the Mayo Clinic. Oxygen saturation is measured by testing a sample of blood from any artery.
A pulse oximeter is a less accurate but valuable means for testing oxygen saturation. A healthy range of oxygen saturation is between 95 and 100 percent, according to the Mayo Clinic.