A blood oxygen level test is a test that measures how much oxygen is in the blood and moving through the arteries, reports the Mayo Clinic. A blood oxygen level test is also known as an oxygen saturation test, reports the Lung Institute.
The blood oxygen level test can be performed with a finger clip or an arterial blood gas test, according to the Lung Institute. The finger clip test involves a clip that is placed on the finger and uses light to determine how much oxygen is in the blood. The arterial blood gas test involves a doctor drawing blood from an artery and then testing that blood to determine the amount of oxygen present in the blood.
The blood oxygen level test is used to understand whether or not a person has problems with bringing enough oxygen into the body. Healthy people have a blood oxygen saturation level of 95 to 100 percent, while people who suffer from lung or other oxygen-rich problems often have a blood oxygen saturation level of less than 90 percent, reports the Lung Institute. If a person has a blood oxygen saturation level that is lower than 85 percent, then he needs to be treated immediately. Otherwise, he may experience tissue dystrophy.