A finger pulse oximeter functions by shining light through your finger. The sensors detect how much oxygen is in your blood based on the way the light passes through your finger.
Pulse oximetry is the technology calculating the results to display a number on the oximeter’s screen that tells you the percent of oxygen in your blood. A finger pulse oximeter can also measures your pulse rate simultaneously.
Blood Oxygen Saturation is the amount of oxygen your blood is holding at the moment, compared with how much it is able to hold. Think of your blood as a sponge. When a sponge becomes full of water we call that 100% staurated, or at capacity. Even if you were to add extra water to the sponge, it could not absorb any more.
Ideally your blood should be at least 90% saturated with oxygen. You can measure your saturation level quickly and simply with a Finger Pulse Oximeter.