Pulse oximetry is a noninvasive and painless test that measures your oxygen saturation level, or the oxygen levels in your blood. It can rapidly detect even small changes in how efficiently oxygen is being carried to the extremities furthest from the heart, including the legs and the arms.
The pulse oximeter is a small, clip-like device that attaches to a body part, like toes or an earlobe. It’s most commonly put on a finger, and it’s often used in a critical care setting like emergency rooms or hospitals.
The pulse oximetry process is as follows:
- Most commonly, a clip-like device will be placed on your finger, earlobe, or toe. You may feel a small amount of pressure, but there is no pain or pinching. In some cases, a small probe may be placed on your finger or forehead with a sticky adhesive. You may be asked to remove your fingernail polish if it’s being attached to a finger.
- You’ll keep the probe on for as long as needed to monitor your pulse and oxygen saturation. When monitoring physical activity capabilities, this will be during the extent of the exercise and during the recovery period. During surgery, the probe will be attached beforehand and removed once you’re awake and no longer under supervision. Sometimes, it will only be used to take a single reading very quickly.
- Once the test is over, the clip or probe will be removed.