In a healthy adult, what range of oxygen saturation levels is generally considered normal?

• A. 80-90%
• B. 90-100%
• C. 85-95%
• D. 75-85%

Answer: (B)

In a healthy adult, oxygen saturation levels that range from 90% to 100% are generally considered normal. This range indicates that the hemoglobin in the blood is adequately saturated with oxygen, which is crucial for the body’s metabolic needs. Maintaining oxygen saturation within this range is essential for ensuring that tissues and organs receive sufficient oxygen to function properly.

Levels below 90% may indicate some form of respiratory or circulatory compromise, and action may be needed to address the underlying cause. Levels above 100% are not typically encountered under normal physiological conditions, as they are unattainable with typical atmospheric oxygen levels. Therefore, the normal range of oxygen saturation is well-defined primarily as 90% to 100%.