The percentage of hemoglobin in the blood that is carrying oxygen.
Oxygen saturation provides an indication of how much oxygen is bound to hemoglobin and available for transport through the bloodstream. It is commonly estimated using a pulse oximeter, which measures peripheral oxygen saturation (SpO₂).
Oxygen saturation can be affected by lung disease, problems with blood flow, altitude, and other conditions. A reading should be interpreted alongside symptoms, clinical findings, and the measurement method rather than in isolation.
QUICK FACT
Oxygen saturation is not the same as the amount of oxygen in the blood. It describes how much hemoglobin is occupied by oxygen, not the total quantity of oxygen being carried.
COMMONLY CONFUSED WITH
Partial pressure of oxygen (PaO₂): a measurement of dissolved oxygen in arterial blood, whereas oxygen saturation describes hemoglobin-bound oxygen.
SEE ALSO
- Hemoglobin
- Oxygen
- Pulse Oximeter
- Respiratory Infection