I was just looking at Mayo's online patient info on CFS (which appears to be readily available as a written pamphlet too.)Nowhere in it does it refer to post-exertional malaise and it actually recommends exercise for CFS sufferers! I could not believe that it would miss such a major symptom as well as suggest something (exercise) that could worsen or even be downright dangerous for a CFS sufferer! While it says to gradually increase exercise, the forms it suggest are walking, swimming, biking, and water aerobics. (What a joke! Tell that to those of us who can't even carry a plate to the table.) It even quotes a study saying 70% of CFS sufferers feel better with a graduated exercise program. As far as I saw, only once, in the introduction, did it say that mental and physical activity "may" worsen symptoms. Furthermore, it does not recognize the severity of the illness. Nowhere that I saw does it mention how disabling this can be.