Chronic Fatigue Syndrome (Myalgic Encephalomyelitis) Differential Diagnoses

Updated: Sep 06, 2020
  • Author: Jefferson R Roberts, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Diagnostic Considerations

CFS is a diagnosis of exclusion. The key diagnostic task is to differentiate it from other disorders that also have a fatigue component. CFS may be distinguished from other causes of fatigue based on the presence of cognitive dysfunction, which is absent in almost all other fatigue-producing disorders. Once a specific cause of fatigue has been diagnosed, CFS is excluded by definition.

It is especially important to rule out systemic disorders, particularly lymphoreticular malignancies, in patients who present with fatigue. Other diseases may be excluded based on the history, physical examination, or laboratory findings. In some cases, these other potential causes of fatigue must be reinvestigated several times.

Differential Diagnoses