Some advanced fitness watches like my Garmin Fenix 6x has built-in Pulse Ox (Oximeter) sensor. Since blood oxygen levels drop at high elevations, the Pulse Ox sensor gives athletes a way to monitor their body's altitude acclimation. But now some doctors say that Pulse Ox can be effective for early detection of COVID pneumonia.
Dr. Richard Levitan's article in the New York Times gives an in-depth look at how Pulse Oximeters can provide early warning of COVID-19:
From the article:
Pneumonia is an infection of the lungs in which the air sacs fill with fluid or pus. Normally, patients develop chest discomfort, pain with breathing and other breathing problems. But when Covid pneumonia first strikes, patients don’t feel short of breath, even as their oxygen levels fall. And by the time they do, they have alarmingly low oxygen levels and moderate-to-severe pneumonia (as seen on chest X-rays).
Normal oxygen saturation for most people at sea level is 94 to 100 percent. Dr. Levitan saw COVID pneumonia patients with oxygen saturations as low as 50 percent.
Even though I had the Pulse Oximeter built into my Garmin Fenix 6x watch on my wrist for the last six months, I rarely got to use it. Living and train at sea level, I've always had readings between 96%-100%.
After reading the article, I immediately tested my blood oxygen levels: