Oxygen saturation refers to the percentage of oxygen that is bound to hemoglobin in the blood. It is an important measure of how well oxygen is being delivered to the body's tissues. Normal oxygen saturation levels typically range from 95% to 100%. Levels below this range may indicate respiratory or circulatory issues. Oxygen saturation is commonly measured using a device called a pulse oximeter, which clips onto a fingertip or earlobe. This non-invasive tool uses light to estimate the amount of oxygen in the blood. Monitoring oxygen saturation is crucial in medical settings, especially for patients with conditions affecting their lungs or heart.