Which SpO2 range is considered normal at sea level in a healthy individual on room air?

Which SpO2 range is considered normal at sea level in a healthy individual on room air?

• A. 95–100%
• B. 88–92%
• C. 90–94%
• D. 95–100%

Answer: (D)

SpO2 reflects how much of the hemoglobin in arterial blood is carrying oxygen. In a healthy person at sea level who is breathing room air, the oxygen in the lungs is sufficient to saturate most of the hemoglobin, so the reading sits in the high 90s up to 100%. Clinically, this normal range is about 95–100%. Values below 95% suggest possible low oxygen in the blood and should prompt further assessment; readings under about 90% are considered hypoxemic and require attention. Small variations can occur due to measurement factors, but the typical healthy baseline on room air is 95–100%.

SpO2 reflects how much of the hemoglobin in arterial blood is carrying oxygen. In a healthy person at sea level who is breathing room air, the oxygen in the lungs is sufficient to saturate most of the hemoglobin, so the reading sits in the high 90s up to 100%. Clinically, this normal range is about 95–100%. Values below 95% suggest possible low oxygen in the blood and should prompt further assessment; readings under about 90% are considered hypoxemic and require attention. Small variations can occur due to measurement factors, but the typical healthy baseline on room air is 95–100%.