Chronic fatigue syndrome: progress and possibilities

Carolina X Sandler and Andrew R Lloyd
Med J Aust 2020; 212 (9): . || doi: 10.5694/mja2.50553
Published online: 6 April 2020


  • Chronic fatigue syndrome (CFS) is a prevalent condition affecting about one in 100 patients attending primary care.
  • There is no diagnostic test, validated biomarker, clear pathophysiology or curative treatment.
  • The core symptom of fatigue affects both physical and cognitive activities, and features a prolonged post‐activity exacerbation triggered by tasks previously achieved without difficulty.
  • Although several different diagnostic criteria are proposed, for clinical purposes only three elements are required: recognition of the typical fatigue; history and physical examination to exclude other medical or psychiatric conditions which may explain the symptoms; and a restricted set of laboratory investigations.
  • Studies of the underlying pathophysiology clearly implicate a range of different acute infections as a trigger for onset in a significant minority of cases, but no other medical or psychological factor has been reproducibly implicated.
  • There have been numerous small case–control studies seeking to identify the biological basis of the condition. These studies have largely resolved what the condition is not: ongoing infection, immunological disorder, endocrine disorder, primary sleep disorder, or simply attributable to a psychiatric condition.
  • A growing body of evidence suggests CFS arises from functional (non‐structural) changes in the brain, but of uncertain character and location. Further functional neuroimaging studies are needed.
  • There is clear evidence for a genetic contribution to CFS from family and twin studies, suggesting that a large scale genome‐wide association study is warranted.
  • Despite the many unknowns in relation to CFS, there is significant room for improvement in provision of the diagnosis and supportive care. This may be facilitated via clinician education.
  • Carolina X Sandler1,2
  • Andrew R Lloyd3,4

  • 1 UNSW Fatigue Clinic, UNSW, Sydney, NSW
  • 2 Queensland University of Technology, Brisbane, QLD
  • 3 Kirby Institute for Infection and Immunity in Society, UNSW, Sydney, NSW
  • 4 UNSW Medicine, Sydney, NSW



Andrew Lloyd is supported by a National Health and Medical Research Council Practitioner Fellowship (1041897). We are grateful for the review of the manuscript by Phillip Peterson MD.

Competing interests:

No relevant disclosures.


remove_circle_outline Delete Author
add_circle_outline Add Author

Do you have any competing interests to declare? *

I/we agree to assign copyright to the Medical Journal of Australia and agree to the Conditions of publication *
I/we agree to the Terms of use of the Medical Journal of Australia *
Email me when people comment on this article

Online responses are no longer available. Please refer to our instructions for authors page for more information.