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Chronic Fatigue Syndrome F024

Last amended 
4 November 2021
Current RMA Instruments

Reasonable Hypothesis SOP

105 of 2021

Balance of Probabilities SOP

106 of 2021

Changes from previous Instruments

SOP Bulletin 226


ICD Coding

  • ICD-9-CM Codes: 780.7, 799.3
  • ICD-10-AM Codes: R53, G93.3
Brief description

This is an unexplained symptom disorder, the main feature of which is severe chronic fatigue, which cannot be improved by bed rest and which is interfering with the person’s work and daily activities.

Confirming the diagnosis

Specific diagnostic criteria (as per the SOP definition) must be met.  This diagnosis should be accepted with caution and only after other chronic conditions, including pre-existing psychiatric diseases, have been satisfactorily excluded.  To confirm this diagnosis you will therefore need a detailed medical report indicating that other potential causes for the patient’s condition have been appropriately investigated and ruled out (see the list below for examples).  An assessment by a psychiatrist will allow psychiatric conditions to be excluded.

Additional diagnoses covered by SOP
  • systemic exertion intolerance disease
Related conditions that may be covered by SOP (further information required)
  • myalgic encephalomyelitis
  • post viral fatigue (syndrome)
Examples of conditions which if present preclude the diagnosis of chronic fatigue syndrome

(this list is not exhaustive, seek medical advice if in doubt)

  • alcohol or other substance use disorder
  • anaemia
  • bipolar disorder
  • chronic obstructive pulmonary disease; asthma.
  • delusional disorder
  • dementia of any type
  • eating disorders - anorexia nervosa or bulimia nervosa
  • hypothyroidism (inadequately treated)
  • ischaemic heart disease
  • major depressive disorder
  • schizophrenia
  • severe obesity
  • sleep apnoea (inadequately treated)
  • unresolved hepatitis B or C infection
Related, unexplained symptom conditions covered by separate SOPs
  • Chronic multisymptom illness
  • Fibromyalgia
  • Somatic symptom disorder
Clinical onset

Clinical onset will be based on the time of new or definitive onset of severe fatigue.

Clinical worsening

The only SOP worsening factor is for inability to obtain appropriate clinical management.  There is limited evidence that treatment interventions (cognitive behavior therapy, exercise therapy, diet, medications) can alter the course of the condition.  The prognosis for functional recovery is generally poor, although a proportion of patients will improve over time.