Several methods are available for measuring SpO2 (peripheral oxygen saturation). The most commonly utilized method is pulse oximetry. Pulse oximeters are highly regarded for their accuracy in non-invasively determining oxygen saturation levels in the blood.

To use a pulse oximeter, one simply places the device on a fingertip. The device then displays the SpO2 percentage, along with the pulse rate. It's important to distinguish that pulse oximeters measure oxygen saturation and pulse rate, not blood pressure.

Alternatively, an arterial blood gas (ABG) test offers another reliable method for assessing SpO2. An ABG test provides a more comprehensive analysis, measuring not only blood oxygen content but also carbon dioxide levels and the blood's pH balance (acid-base equilibrium). Significant deviations in blood pH, whether excessively acidic or alkaline, can indicate underlying health concerns. Therefore, an ABG test is considered a versatile and in-depth diagnostic tool.