I apologize in advance for opening the discussion about whether we can call ME/CFS a disease or not. This topic is discussed sporadically in other threads and I thought it might be useful to make one for it, to collect our thoughts about it in a more structured manner. This subject may seem trivial, but it’s something that comes back a lot, in just about every advocacy move we do, whether you’re making a flyer, doing an interview, contacting a politician or just want to inform some friends. The prevailing idea is that it’s best not to use the term disease because that implies a reference to a specific pathological state, which is not yet known in ME/CFS. So other terms such as illness or syndrome might be more appropriate. There are others who take a different view, most famously the IOM-report. In the final speech at the NIH conference, Maureen Hanson said: “this is not a syndrome it's a disease.” I’ve just read this old article titled: “The confusion between disease and illness in clinical medicine.” The impression I’ve got from it is this: in the 19th century when great scientists like Rudolf Virchow were beginning to discover the organic basis of illnesses, they wanted a word for the pathological changes they discovered and a different word for the symptoms that might correspond with it. To me, that makes sense because research was mostly about how these factors relate to each other. In other words: do the symptoms relate to the biological abnormalities; can the former be explained by the latter? The way we currently use the term disease however is different and obfuscate this distinction, because we use it for both the pathological changes and the symptoms we think correspond with them. When we say multiple sclerosis is a disease we do not only mean the damage to the myelin sheath of neurons, but also the symptoms of muscle weakness or fatigue that are associated with it. So it seems that the term disease is now used to make a distinction between illnesses where a pathological state corresponds to symptoms (= disease) and others where no such pathological is yet discovered (= not disease). To me, that doesn’t make much sense. There isn’t a line you can draw there. I think that even in illnesses where a pathological state is known, it’s difficult to explain all the symptoms patients have. The fatigue in MS, for example, is still poorly understood and I suspect this is more the rule than the exception. Another problem is that the term disease versus the alternative term, syndrome is not used consistently within medicine. Down syndrome for example has a known pathology, so would be better described as a disease, while little is known about the pathology of Alzheimer’s disease or Parkinson’s disease, so perhaps these could also be described as a syndrome, depending on how you look at it. Depression is occasionally referred to as a disease but hardly ever as a syndrome. So I don’t think we make a big mistake or that any insight is lost in using the term disease for ME/CFS. It’s true that ME/CFS is probably quite heterogeneous, but perhaps the same is true of Alzheimer’s disease or Parkinson’s disease. The symptoms of lupus patients can vary widely and MS patients have different illness trajectories which scientists cannot yet explain. So these diseases might also be divided into subgroups based on a different underlying pathology somewhere in the future. It’s hard to name a disease where scientists aren’t trying to subgroup the patient population in the hope of better understanding and treatments. It’s also true that little is known about the pathology of ME/CFS but we do have some clues: observed cytokine aberrations that correspond to illness severity, metabolic changes that have been observed by multiple groups and abnormalities on exercise tests such as chronotropic intolerance or an earlier onset of the ventilatory threshold on a second CPET. None of these is certain, but we’re getting there. What we usually want to tell people, when we explain what ME/CFS is, is that it's a condition that keeps people terrible ill for decades. That some people suffering from it, are bedbound for years on end and that some parents affected by it are no longer to care for their children or even themselves. We want to say that many people are suffering from this condition and that they not only have similar symptoms, disability and prognosis but that in most cases it started after an infection from which they never recovered. We want to say that scientists are studying the molecular basis of this condition in the hope of finding a treatment. In my opinion, this description is not covered by the term ‘syndrome’. Most people would use the term ‘disease’ for what I’ve explained above. So if we as ME/CFS advocates emphasize that ME/CFS is not a disease, we might be causing more confusing instead of avoiding it. Also, as explained in this Wikipedia article: ill without being diseased describes a situation where a "person perceives a normal experience as a medical condition, or medicalizes a non-disease situation in his or her life." So by avoiding the term disease, we might give a misleading impression of ME/CFS. These are just some thoughts. Interested in what others make of this and whether they use the term disease or not for ME/CFS.