Siren, just read over the thread you posted on about Wolfy's latest episode. Unfortunately, shortness of breath has one of the broadest differential diagnoses in all of medicine. It can be caused by a huge number of problems, but you're correct in your assessment the cause is probably found with the heart, blood vessels, or lungs, (or a combination of them) as these are the chief organs responsible for delivering adequate oxygen to the body. With just the information in the thread, there's not much of a way to determine what exactly is wrong. There's a LOT more questions a doctor would want to know, and of course, the physical exam and lab tests are vital parts of any diagnosis, so I won't even attempt to make a guess, but if this problem continues, get to a doctor ASAP! Shortness of breath can be a symptom of some very serious diseases, as well as some more benign ones, so don't take it lightly.
I wish Wolfy the best and if you have any specific questions, don't hesitate to drop me an email or post it on the board.
Actually, the low oxygen saturation doesn't really tell us much more than being short of breath. It tells us his blood doesn't have as much oxygen in it as it ordinarily could (which is pretty much what our body is telling us when we get short of breath). The problem is that there are lots of reasons for poor oxygen saturation: anemia as another poster mentioned, heart failure, pneumonia, all different kinds of diseases of the blood, lungs, and blood vessels. If he didn't have an acute infection like pneumonia, it's possible that his condition is chronic and you want to get him evaluated for that just in case.