I agree that there probably is a lot of misdiagnosis due to laziness or not being willing to spend the money (depending on which country or whether you're in a managed health care system), but I am not convinced that there is no ME at all. In most other conditions, people improve with exercise. We do not. Now, maybe, that's because of a total lack of appropriate treatment (due primarily to lack of appropriate investigation--they mainly look for the main diseases that are relatively easy/expected to find in most people: Lupus, diabetes, multiple sclerosis, rheumatoid arthritis, coronary artery disease, and whatever the big thyroid disease is which would cause TSH to be outside lab standards... and then they stop looking, so of course they cannot treat the problems these patients have). But I don't think we would have so much in common with one another (those of us that do fit CCC), if we didn't have related disease process. Muscles that continue to lose power even after stopping use? That's fairly novel. Besides us, only in MG do muscles lose power with use (and in that disease I don't know if they continue after stopping). Abnormal exercise test on the second day? We don't know if that would show up in these other people that report PEM or if they're experiencing something different (something else equally valid, but some other disease process). Only way to check would be to test some of them. (Jason says some 12-17% of MDD patients report PEM, so it wouldn't have to be grandma with Parkinson's.) Low NK function does appear in other diseases. It's more like ANA which would identify a general process, not a specific disease. Same with RNAse-L stuff. However, we may be able to identify a unique profile of tests that show up that indicate ME (or subsets thereof), as a set. Kind of like diagnosing rheumatic disease, you would diagnose from lab tests and symptoms combined. Klimas and even some of the others on this forum would know better than me.