Mine certainly do; that's one of the ways I know I need to get medical treatment. One of the things everyone with COPD should do is work with your doc, whether, a pulmonologist or PCP, using an action plan to figure out what your triggers are and what you should do when/if any of them occur. Reduced O2 levels that aren't explained by a change in altitude or activity level are usually a good sign that something's wrong. It's one of the signs of COVID, and with people who don't keep track of their O2 sats regularly, it took them completely by surprise. I don't use O2 when I'm sitting or working at the computer, so if I need O2 then, something's definitely wrong.

Here's a link where you can download an action plan to take with you to your next appointment with your doc:

https://www.copdfoundation.org/Learn-More/Educa...