Patient of CFS may report some additional symptoms, such as muscle weakness, hypersensitivity, cognitive dysfunction, digestive disturbance, orthostatic intolerance, poor immune response, depression and respiratory problems.

Though, CFC is to have an incidence of four adults per 1,000 in United States , but for unknown reason CFS occurs most often in people in their age of 40s and 50s, it is more often in women than men, it is less prevalent among the adolescents and children.

CFS name is controversial itself as advocatory groups and some experts believe it trivialized illness and also have supported effort to change it. Some patients report that critical reductions in levels of the physical activity and reduction in complexity of activity also been observed.

Disability and severity of symptoms is same in both genders with disabling chronic pain, despite common diagnosis, functional capacity of individuals with CFS varies greatly.

There are no physical signs or medical tests to diagnose CFS, and so testing is used commonly to rule out some other potential causes for the symptoms. The criteria of year 1994 require presence of only 4 symptoms beyond the fatigue, where criteria of 1988 require 6-8. Many patients do not recover fully from CFT with treatment even, and is no curative option universally effective. Other CFS treatments have been proposed but the effectiveness of those treatments has not been confirmed yet.