Vital signs, those fluorescent green numbers that beep, ding, and dash across black screens on the monitors in hospital rooms, have become a new source of angst during the coronavirus pandemic. One of ...

The blood in your body delivers oxygen to all of your cells. When you breathe and draw fresh oxygen into your lungs, red blood cells bind with the oxygen and carry it through your bloodstream. On a ...

A dangerously low oxygen level—usually below 92%—can cause shortness of breath, confusion, chest pain, or fainting. It’s often triggered by lung or heart conditions like COPD, asthma, or heart ...