The chronic fatigue syndrome is an illness of unknown etiology
characterized by severe fatigue, myalgias, lymphadenopathy,
arthralgias, chills, fevers, and postexertional malaise.
Recognizing chronic fatigue syndrome is primarily a method of
exclusion with no definitive diagnostic test or physical
findings. As research continues to delve into the many
possible etiologic agents for chronic fatigue
syndrome–infectious, immunologic, neurologic, or psychiatric
alone or in combination–the answer remains elusive. What is
known is that chronic fatigue syndrome is a heterogeneous
disorder very possibly involving an interaction of biological
systems. Therefore, chronic fatigue syndrome may describe a
large subset of patients, each exhibiting unique symptoms and
serologic profiles dependent on the nature of the onset of
illness and the genetic profile of individual patients.
Kakumanu S, Yeager M, Craig TJ