AdvertisementScientists Edge Closer To Elusive Lab Test For Chronic Fatigue SyndromeJuly 31, 2017Miriam E. TuckerfacebookEmailIn addition to profound exhaustion that isn't relieved with sleep, the illness now called ME/CFS includes flu-like symptoms, muscle pain, "brain fog" and various other physical symptoms, all of which typically worsen with even minor exertion. (Malte Mueller/Getty Images)