Chronic Fatigue Syndrome

Chronic fatigue syndrome (CFS) is a chronic disease that potentially affects about two million Americans. The United States Public Health Services initially described it during an epidemiological study of Los Angeles County during the summer of 1934. Chronic fatigue syndrome, also called myalgic encephalomyelitis, is a complex multisystem disease commonly characterized by severe fatigue, cognitive dysfunction, sleep problems, autonomic dysfunction, and post-exertional malaise severely impairing activities of daily living. Outcomes become worse due to the condition remaining undiagnosed for years, secondary to inadequate medical teaching on the subject, provider bias, and confusion regarding diagnosis and treatment of the disease.

CFS does not only present with fatigue but also cognitive dysfunction and impairment of routine functioning that persists for six months or more. CFS is a biological condition, not a psychological disorder. The exact pathogenesis remains to be fully understood. Various mechanisms and biochemical changes have been implicated that affect immune function, hormonal regulation, and response to oxidative stress. It also includes natural killer cell dysfunction and/or T-cell dysfunction, elevated cytokines, and autoantibodies. The infectious cause has been proposed, but no causal relationship has been identified.

Patients with CFS can sometimes present to the emergency department with a list of complex symptoms, such as orthostatic intolerance, postexertional malaise (PEM), fatigue, and diarrhea.