Blood oxygen levels refer to the amount of oxygen circulating in the blood. Normal blood oxygen levels fall between 75 and 100 millimeters of mercury (mm Hg) on arterial blood gas (ABG) test results.

Lindsay Modglin is a nurse and professional writer who regularly writes about complex medical topics, as well as travel and the great outdoors. She holds a professional certificate in scientific ...

Oxygen therapy can help people with certain health conditions, such as emphysema, sleep apnea, or severe COVID-19, get enough oxygen to stay well and function. Oxygen therapy may be a temporary ...

A dangerously low oxygen level—usually below 92%—can cause shortness of breath, confusion, chest pain, or fainting. It’s ...