Oxygen Saturation in Whole Blood (Pulse Oximetry)

How This Test Works

A small sensor attached to your finger shines light through your skin to detect the amount of oxygen bound to hemoglobin. This process is painless and takes only a few seconds. The sensor converts the light absorption into a numerical value representing your oxygen saturation percentage.

When You Might Need This Test

Doctors may order this test to evaluate lung function, check for conditions like low oxygen levels (hypoxia), monitor chronic illnesses (e.g., heart or lung disease), or assess response to treatments. It’s also commonly used during surgeries or in critical care settings.

What to Expect During the Test

You’ll likely be asked to sit or lie down while the sensor is placed on your finger. The test is quick and doesn’t require any special preparation. You may feel a slight pressure or warmth from the sensor, but it shouldn’t cause discomfort.

Possible Results and Interpretation

Results are typically reported as a percentage (e.g., 95%). Normal values can vary slightly by age and health status, but generally, healthy adults usually have levels between 95% and 100%. Lower values may indicate problems with breathing, circulation, or other health conditions.