These, are the same thing they are just different names: In the U.K it is commonly refered to as Myalgic encephalomyelitis (M.E), it has also been called post viral fatigue syndrome (P.V.F.S), as well as yuppie flu. In the U.S.A it is refered to as Chronic fatigue syndrome (C.F.S), It has also been refered to as tapanui flu, and I'm sure there have been other names for it, but M.E and C.F.S are the most common names used to describe this condition. These are some of the conditions that have been refered to as sister illnesses, meaning they are closely related: Multiple chemical sensitivities, (M.C.S), Gulf war syndrome (G.W.S), Myofascial pain syndrome (M.P.S), and Fibromyalgia. There are also many other similar types of condition which I havent mentioned. The jury seems to be out on the question of whether C.F.S is the same as Fibromyalgia, but certain doctors it would appear, believe that Fibromyalgia is a form of C.F.S. So who knows maybe, just maybe, M.C.S, G.W.S, M.P.S, as well as certain other simmilar conditions I haven't mentioned, are all just variations of C.F.S. It's all a bit confusing really isn't it. At the end of the day, it is blatantly obvious that they are all immuno type conditions, which have in some cases very strong similarities.