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Minimum overnight oxygen saturation

Breathing tests · also printed as Min SpO2, Minimum SpO2, Lowest SpO2, Nadir SpO2, Min saturation

Typical UK adult range88 % and above

Above 88 percent is typical.

What this test measures

The lowest blood oxygen saturation recorded during the night.

Why doctors request it

Part of every sleep study, showing how deep the oxygen dips go during pauses in breathing.

What commonly pushes it up

Supplemental oxygen

What commonly pushes it down

Sleep apnoea
Lung disease
Alcohol and sedatives

Everyday reasons for a value outside the range

A brief probe artefact can produce a spurious low value, which scorers usually remove

About the sample

Overnight recording.

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

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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.