What is the ICD‑10 code for post‑viral fatigue syndrome?

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ICD-10 Code for Post-Viral Fatigue Syndrome

The ICD-10 code for post-viral fatigue syndrome is G93.3, which falls under "other disorders of the brain" in the neurological conditions chapter. 1, 2

Code Classification Details

  • Post-viral fatigue syndrome is classified as a neurological condition by the WHO under ICD-11 code 8E49, though the ICD-10 equivalent remains G93.3. 1

  • This code encompasses chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and is listed as a sub-category under chapter G93 (other disorders of the brain). 2

  • The classification explicitly designates this as Post Viral Fatigue Syndrome (PVFS) in the WHO International Classification of Diseases. 2

Clinical Context for Coding

Post-viral fatigue syndrome manifests as persistent fatigue, cognitive difficulties, and post-exertional malaise following viral infections. 1 The syndrome includes:

  • Disabling fatigue lasting beyond typical recovery timeframes 1
  • Musculoskeletal pain and neurocognitive difficulties 3
  • Mood disturbance and unrefreshing sleep 1
  • Autonomic dysfunction 1

Important Coding Considerations

The diagnosis requires exclusion of other medical conditions, including psychiatric disorders, before applying this code. 2 Key diagnostic criteria include:

  • Symptoms must persist beyond 4 weeks after mild acute infection (rather than waiting 12 weeks as some definitions suggest). 4
  • For post-Q fever fatigue syndrome specifically, symptoms must persist >1 year after symptomatic acute infection with elevated antibody titers and no organ involvement. 4
  • The fatigue must not have developed before other symptoms. 2

Prevalence and Demographics

  • Estimated worldwide prevalence is 0.4-1 percent of the population. 2
  • Peak age of onset is between 20-40 years with a female-to-male ratio of 6:1. 2
  • Post-infective fatigue syndrome occurs in approximately 12% of patients at six months following acute viral infections. 3

References

Research

Creatine and post-viral fatigue syndrome: an update.

Journal of the International Society of Sports Nutrition, 2025

Research

Chronic fatigue syndrome/myalgic encephalomyelitis: an update.

International journal of immunopathology and pharmacology, 2010

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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