Some medical phenomena are not diseases, they're collective terms for symptoms with an unclear cause. "CFS", among others, is such a term. As underlying causes

Some medical phenomena are not diseases, they're collective terms for symptoms with an unclear cause. "CFS", among others, is such a term. As underlying causes are identified, groups of patients ideally get moved off the label and categorized more appropriately according to what they are actually suffering from. CFS is not a diagnosis, it's a label for a syndrome which should only be applied after a medical practitioner has exhausted all her diagnostic capabilities without conclusive results. CFS is not something that should ever be on top of the list, it's only a fallback for when you reach the end of the list, and it has to be this way by definition. However, these syndromes sometimes develop a life of their own. It can be because our diagnostic means still have glaring weaknesses. Or because doctors don't want to explore something any further. Or because a syndrome becomes a cultural phenomenon. This is parodied pretty well in an animated Dilbert episode with "Chronic Cubicle Syndrome". Because of this cultural baggage (which affects physicians as well) it might be better to move away from a syndrome-based nomenclature for these things. Idiopathic Chronic Fatigue would be a much better term. That's why I think studies on groups of patients labeled with a syndrome are net-beneficial while every patient actually "diagnosed" with CFS is a medical defeat.