What Is the Oxygen Level in a Person's Body?


Quick Answer

The oxygen level in a person's body reveals how much oxygen is in the blood, reports USCF Medical Center. Oxygen enters the body through the lungs and then moves to the bloodstream, where protein molecules – hemoglobin – in red blood cells carry oxygen to all parts of the body.

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Full Answer

Oxygen level is usually found through oximetry, USCF Medical Center states. This test measures oxygen saturation of the blood, or the percent of hemoglobin carrying oxygen. An instrument on the finger or ear uses light to determine how much oxygen is present. A normal reading is around 95 to 100 percent.

An arterial blood gas study examines the oxygen level in blood drawn from the wrist artery, explains USCF Medical Center. A machine measures the amount of dissolved oxygen. Normal levels are 80 to 100 millimeters of mercury.

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