While trying to research the cause of my symptoms, which consisted of a full-on CFS/ME episode lasting about 2-3 months .... slowly fading away now .... I happened upon the issue of Mitochondrial Dysfunction. I had taken medications which are known to cause damage to the mitochondrial system (energy producing cells in the body). Reading about children born with mitochondrial dysfunction, I found little difference between their symptoms and those of CFS/ME. Mitochondrial Disease (or the more temporary version - "Dysfunction") can be adult-onset. It can come from toxins such as medications, environmental influences, or life triggers which interact with the genetic predispositions in a person. The end result is the same - inability for the body to produce energy. This is seen on every level, as mitochondria exist both in muscle tissue, other body tissue, brain, and organs. As far as I know, mitochondrial dysfunction doesn't "show" on any standard tests. One would need a muscle biopsy, and even then, it isn't always evenly distributed throughout the body, so could be concentrated away from the particular muscle being checked. Someone experiencing mitochondrial dysfunction could have system-wide symptoms of "inefficiency" that would look like a whole host of other diseases, yet with no abnormal test results, and no evidence of current infection. Sounds familiar right? It wouldn't improve on its own, as damaged mitochondria would replicate more damaged mitochondria. Unless exercise is introduced, possibly the passage of time allowing for healing - it would depend upon what caused the damage in the first place, and whether its gone. This video by Dr. Terry Wahls has "gone viral" lately, and for good reason: Its a bit long but worth watching through to the end. She gets into the meat of it in the second half. But they say Fibro patients respond quite well to juicing, and mitochondrial supplementation, and careful, guided, increasing exercise. As exercise is one of the few things on this earth which can stimulate mitochondrial biogenesis (development of brand new baby mitochondria). Why isn't CFS/ME simply a systemwide energy deficiency due to mitochondrial dysfunction? Thanks.