Oxygen Saturation, Arterial

Abbreviation: SaO2

Panel: Blood Gas Tests · All blood gas tests

Typical adult reference range

Conventional units95–100 %
SI units95–100 %

Ranges vary between laboratories and methods — compare your result with the range printed on your own report.

What a high or low result can mean

Low oxygen saturation, arterial: low values may occur in lung disease, hypoventilation, and right-to-left shunting.

These are associations, not a diagnosis: the same result can have several causes, and your clinician interprets it with the rest of your results and history.

Good to know

Measured SaO2 by co-oximetry can differ from pulse oximetry estimates.

Please note: Reference ranges vary between laboratories, and between the methods and instruments they use — the range printed on your own report is the one your result should be compared with. A result outside the range is not by itself a diagnosis, and a result inside it does not rule out illness. These pages are an educational summary, not medical advice: always discuss your results with the clinician who ordered them, who can interpret them in the context of your health and history.