Okay, @Nick_Radov, I'm obviously out of my league in this discussion, but what I meant was the kind of more severe infections that the experts here have mentioned. Influenza, mainly. I can't speak for others, but I haven't had a "cold" that affected my respiratory function in any way that I can remember, and I believe we have a long track record of successfully returning to diving after the common cold. I last had the flu about 20 years ago, but if I had it again today, and it knocked me out the way it did back then, I would consider being tested before returning to diving. I understand that most primary care physicians wouldn't have a clue about respiratory infections and returning to diving, and insurance wouldn't cover the testing, but maybe as individual divers we need to look out for ourselves and push for additional testing when the general public would not. Looking out for myself as a diver who decided to venture far from medical help on some dives, I have pushed for additional cardiac testing (at my own expense) when there was nothing to suggest to my primary care physician that it was "necessary."