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Oxygen saturation (blood gas)

Blood gases · also printed as sO2, SaO2, SO2 (blood gas), O2 sat (ABG), Oxygen saturation (arterial)

Typical UK adult range95 to 100 %

Ranges vary between laboratories; the range printed on the report takes precedence.

What this test measures

The share of haemoglobin carrying oxygen, measured directly on a blood gas sample.

Why doctors request it

Part of an arterial blood gas, and the value a finger probe is trying to estimate.

What commonly pushes it up

Breathing supplemental oxygen

What commonly pushes it down

Lung disease
A venous sample, which normally reads around 70 percent and is not comparable

Everyday reasons for a value outside the range

Venous saturation is much lower by design

About the sample

The report should say arterial or venous.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

Got a report with Oxygen saturation (blood gas) on it?

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This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.