SpO2 (Blood Oxygen) — What It Means and How QRNT Tracks ItUpdated 2 days ago

What it is

SpO2 measures the percentage of oxygen-saturated hemoglobin in your blood. A healthy resting SpO2 is typically 95–100%. Readings below 94% at rest may warrant attention.

QRNT tracks SpO2 using its optical PPG sensor — the same sensor used for heart rate and HRV — which shines light through your skin and measures how much is absorbed by oxygenated vs. deoxygenated blood.

When it matters

• Altitude: SpO2 naturally drops at elevation. QRNT helps you monitor acclimatization during hikes, travel, or training at altitude.
• Sleep quality: Drops in SpO2 during sleep can indicate disrupted breathing. If you notice consistent low readings overnight, it's worth discussing with a healthcare provider.
• Recovery: Healthy, stable SpO2 is a baseline sign your body is functioning well. Significant drops alongside low HRV can indicate your body is fighting something.

Important: QRNT SpO2 readings are intended for wellness tracking and are not a medical device. Do not use them to diagnose or manage medical conditions.