Blood Oxygen Saturation (SpO2)
The percentage of hemoglobin in arterial blood carrying oxygen, measured noninvasively by a pulse oximeter. Optimal range: 95-100%; below 90% is clinically low.
What it measures
The percentage of hemoglobin in arterial blood carrying oxygen, measured noninvasively by a pulse oximeter. A basic window into respiratory and circulatory function.
Why it matters
Persistently low SpO2 signals hypoxemia, which can reflect sleep apnea, lung disease, or altitude effects. For most healthy adults it simply confirms normal oxygen delivery.
Optimal ranges
Sourced targets, not just lab reference ranges. Lab ranges describe the population; these describe where the evidence says you want to be.
| Range | Context |
|---|---|
| 95-100%; below 90% is clinically low | World Federation of Societies of Anaesthesiologists tutorial: oxygen saturation in healthy patients of any age should be 95% or above. |
How to improve it
- 1
Treat sleep apnea if suspected (snoring, daytime fatigue)
- 2
Aerobic exercise and breathing training
- 3
Quit smoking and avoid secondhand smoke
- 4
Seek evaluation for persistent readings below 94%
Connected to
Goals
Longevity Lab Report
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Educational information, not medical advice. Talk to your doctor before acting on any biomarker result.