I have been wondering about CFS too. I do have a fibro diagnosis as I have already mentioned. I feel like they just keep doing tests and finding no answers, but no one is saying CFS. I know what it is not: anema, apnea, vit d deficiency, RLS, narcolepsi, lack of sleep, insomnia. I was switched on to Cymbalta for the fibro, but now they are taking me off to see if that is the cause of the fatigue. They have run so many blood tests. I am so frustrated. I am on naproxine, but they are trying to get me to stop that to see if I can just handle the fibro pain without it. I am so tired of being tired.