I read a piece in US NEWS today. Headline:

Chronic Fatigue Syndrome: The CDC Says It's a Big Problem

Now, I'm not making light of this situation that may grip someone, but here's the symptoms and some commentary as reported:
profound fatigue–especially after mental or physical exertion–joint pain, impaired memory, problems sleeping, and often depression. The cause isn't known and there's no cure, but drugs, physical therapy, occupational therapy, and psychological counseling can ease distress. "The most important thing to understand is that the fatigue component creates a significant disability," says Julie Gerberding, director of the CDC. "There is no gold standard test," she explains, and doctors first have to rule out other illnesses before diagnosing CFS. It's believed that early detection is related to better outcomes and greater likelihood of improvement.

So there's no way to determine, no "gold standard test", to see if one has this "disease". I'm lost and very interested to see what the CDC's studies come up with.