Just to follow up on this morning’s post, I did indeed go out to Walgreens and buy a pulse oximeter today:
Why not? It was cheap, and since I have breathing problems anyway it might be handy to have around. My reading of 97 percent is fairly ordinary. Below 90 percent is considered low. Below 85 and you might start thinking about checking into the ER for a COVID-19 test.
BY THE WAY: A reader emailed to tell me that you can get an oxygenation reading using an app on your cell phone. Don’t do it. I did a quick scan of the literature and phone apps got slammed pretty hard. If you’re going to bother with this at all, just buy a real one.