An oxygen saturation chart shows the ratio between the amount of oxygen-saturated hemoglobin and the total amount of hemoglobin in a person's blood, explains the Mayo Clinic. The healthy range for oxygen-saturated hemoglobin is generally between 95 percent and 100 percent.
Hemoglobin becomes saturated with oxygen through a process known as aerobic metabolism. Aerobic metabolism is one of the by products of breathing, explains the Mayo Clinic. If oxygen saturation levels drop too low, a person runs the risk of passing out and eventually dying. Oxygen saturation levels fluctuate depending on elevation, but they should generally stay within the range of 95 percent and 100 percent. Extremely high elevations may be slightly below this range.
Oxygen saturation is measured via a pulse oximeter, notes Johns Hopkins Medicine. A pulse oximeter is a device that is attached to a patient's finger and measures oxygen levels with infrared lights. These results are then printed onto an oxygen saturation chart that shows the patient's oxygen saturation level in relation to the healthy range for oxygen saturation levels.