Serum Arterial Oxygen Saturation (SaO₂) over Time

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like shortness of breath, fatigue, or rapid heartbeat. It’s also used to evaluate lung function, check for conditions like pneumonia, heart failure, or blood disorders, or monitor treatment progress for chronic respiratory diseases.

What to Expect Before the Test

You’ll receive an arterial blood draw, usually from a small incision in your arm or wrist. The process is quick but may cause a brief sting. If you’re anxious, let your provider know—they can use numbing cream or provide reassurance.

What Happens During the Test?

Blood is drawn into a special tube that preserves oxygen levels. The sample is analyzed immediately or sent to a lab to measure oxygen saturation levels at different time points (often over minutes or hours).

What Does the Test Result Mean?

Results show how oxygen is delivered to your tissues. Lower-than-expected levels may indicate poor lung function, reduced blood flow, or other health concerns. Your provider will interpret results in the context of your symptoms and overall health.