There are a lot of stories out there like that.Architect wrote: ↑Sun May 29, 2022 3:12 pmApple watch saved my brothers life, I don't remember all the technicalities he shared, he felt fine but his resting heart rate was 120, abnormal sinus rhytem. He's very stubborn, believed watch was malfunctioning, cause he felt fine. Family finally convinced him to visit ER, he finally went late that evening, diagnosed AFib.
My Fitbit charge 5 rarely detects sp02, so I purchased a finger oximeter, which works 50%
My daughter found out today she has Covid--she has mild-moderate cold symptoms. Her Apple Watch kept bugging her last Friday because her heart rate was going over 120 at rest

So last night I had a full battery on my AW and used the recording pulse oximeter. The AW only took 3 Blood Oxygen readings in the early part of my sleep cycle--I don't know why it stopped after that. But those 3 readings about 30 minutes apart averaged 94.8% Sp02. The recording pulse oximeter took readings continuously during the night which averaged out to 94%, and from the looks of the graph stayed between 93% and 94% pretty much all night (good news!).
So while the AW had almost the same reading, it doesn't increase my confidence in the accuracy of the AW, because the readings seem too random. It could too easily miss apnic events, or underscore normal breathing.
I still want to try both a few more nights, but I don't think the AW is a reliable indicator of blood oxygen during the night, particularly for those of us who have diagnosed apnea.