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 ...

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

The blood oxygen sensor featured in Apple Watch Series 6 and 7 is “not intended for medical use,” Apple says. That seems odd, considering that low blood oxygen is a serious medical condition. If the ...