Blood Oxygen Saturation

The percentage of hemoglobin in the blood that is bound to oxygen, typically measured non-invasively using a pulse oximeter. Normal blood oxygen saturation is generally 95-100%, and levels below 88-90% are considered clinically concerning and may indicate hypoxemia (dangerously low blood oxygen). For people with COPD and other respiratory conditions, monitoring O2sat during exercise is important because feelings of breathlessness do not always correlate with actual oxygen levels — patients may feel dangerously short of breath while their O2sat remains safe, or conversely may not realize their oxygen has dropped to unsafe levels. This disconnect makes O2sat monitoring a valuable tool for managing exercise safely and reducing unnecessary anxiety.