title: Chronic fatigue syndrome.
abstract: 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.
authors.affiliation: Pennsylvania State University, College of Medicine, Hershey, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kakumanu
authors.forename: M
authors.initials: M
authors.lastname: Yeager
authors.forename: T J
authors.initials: TJ
authors.lastname: Craig
mesh_terms: D002986:Clinical Trials as Topic; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D007239:Infections / Q000150:complications; D008297:Male; D011379:Prognosis; D013315:Stress, Psychological / Q000150:complications