Oxygen is absorbed by a protein in your blood called hemoglobin. When you breathe, your lungs load up blood cells with oxygen, then the pumping of your heart circulates the oxygen-rich blood through ...

Normal blood oxygen level is either 95%-100% SpO2 on an oximeter or 80-100 mm Hg from an ABG test. ABG tests are more accurate than pulse oximeters, which have a ...