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 ...

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.

In this era of fitness trackers, we have easy access to our heart rate at any given moment. Every so often, a number catches your eye as it flashes on your Garmin or Apple Watch while you're sitting ...

A normal heart rate is between 60 to 100 beats per minute (BPM), but it can vary by person. A heart rate slower than 60 BPM can be a sign of anything from a high fitness level to hypothyroidism. A ...