Which test is performed to diagnose hypoxemia?

Pulse Oximetry:

Pulse oximetry is a non-invasive test that measures the oxygen saturation (SpO2) of a patient's blood. It is performed by placing a small probe on a fingertip, earlobe, or forehead. The probe emits light of two different wavelengths, one absorbed by oxygenated hemoglobin and the other by deoxygenated hemoglobin. The difference in absorption between the two wavelengths is used to calculate the SpO2.

A normal SpO2 level is typically between 95% and 100%. Levels below 90% are considered to be hypoxemia. Pulse oximetry is a simple and painless test that can be used to quickly and easily assess a patient's oxygen saturation.