During the day, blood oxygen levels—also known as oxygen saturation levels —generally fall between 95% and 100% in healthy people, whether asleep or awake. This is considered normal.

The technology then detects the color of your blood as a sign of how much oxygen is present. In general, a “normal” or safe blood oxygen level should be somewhere between 95% and 100%.

Participants were randomly assigned to receive high oxygen (hyperoxia) or a lower amount of oxygen intended to maintain normal blood oxygen levels (normoxia).

It’s worth noting that normal blood oxygen levels are considered 95% and higher.

Participants were randomly assigned to receive high oxygen (hyperoxia) or a lower amount of oxygen intended to maintain normal blood oxygen levels (normoxia).

Participants were randomly assigned to receive high oxygen (hyperoxia) or a lower amount of oxygen intended to maintain normal blood oxygen levels (normoxia).

Normal blood oxygen levels are considered 95% and higher. And while a person’s heart rate usually drops during sleep, the researchers found that—especially for the group drinking alcohol—the ...