What is Oxygen Saturation?

Oxygen saturation refers to the percentage of hemoglobin molecules saturated with oxygen. Hemoglobin molecules can each carry four oxygen molecules; the oxygen binds or attaches to hemoglobin molecules. Oxygen saturation provides information about how much hemoglobin is carrying oxygen, compared to how much hemoglobin is not carrying oxygen.

Why is Oxygen Saturation Measured?

Healthcare providers measure oxygen saturation because it provides information about a client’s state of health. The body’s tissues and organs require oxygen for metabolism, and oxygen saturation can reveal whether there is sufficient oxygen in the blood or whether the client is in a state called hypoxemia (insufficient oxygen in the blood).

Oxygen saturation levels can influence clinical decisions about whether the client is receiving sufficient oxygen and/or requires supplemental oxygen. Oxygen saturation levels are also monitored during and after surgeries and treatments and to assess a client’s capacity for increased activity.