But there is a simple device that can detect this drop in blood-oxygen well before you start getting out of breath. It's a fingertip gadget called a pulse oximeter.

Apple's new Apple Watch Series 6 goes all-in on health care, including a new feature to measure blood oxygen level -- a vital sign that's been helpful monitoring COVID-19, among other things.

It’s not a blood pressure measurement, which would be impossible to do without additional hardware, instead Apple is adding the ability to determine the oxygen saturation of the blood.

Some doctors think pulse oximeters, which measure blood oxygen levels, are useful ways for COVID-19 patients to monitor symptoms. They’re sold out at major retailers, so people may be turning to ...

Blood oxygen monitors said that hospitalized Asian, Black, and Hispanic COVID-19 patients had higher blood oxygen levels than they actually did, according to a new study.