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Diagnosis (IOM/NAM 2015)

The IOM/NAM 2015 criteria are the current clinical standard for diagnosing Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Diagnosis is based on history and exam consistent with the criteria and exclusion of common mimics. There is no single laboratory test that confirms ME/CFS; it is a clinical diagnosis anchored in established features.

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Core Diagnostic Criteria (IOM/NAM 2015)

  • Substantial activity reduction/impairment >6 months due to fatigue not alleviated by rest.
  • Post-Exertional Malaise (PEM).
  • Unrefreshing sleep.
  • At least one: cognitive impairment or orthostatic intolerance (OI).

Clinical assessment, not a single test.

Use history, exam, and targeted workup to exclude common mimics (e.g., anemia, thyroid disease, primary sleep disorders). Document post-exertional symptom worsening (PEM) and consider orthostatic intolerance (OI) with simple lying→standing vitals.

Practical Assessment Flow (10–15 min)

  1. History. Ask about activity reduction (>6 months), PEM (delayed 24–48 h crash after small efforts), unrefreshing sleep, and cognitive or upright symptoms.
  2. Screen for OI. Lying→standing HR/BP at 0/2/5/10 min and symptom capture; note heat/shower/standing intolerance.
  3. Targeted rule-outs. Order focused labs per Workup page (CBC, CMP, TSH, ferritin/iron studies, B12, vit D, CRP/ESR; plus context-driven tests).
  4. Document. Use concise language (see below) and schedule safe follow-up. Avoid changes that may provoke PEM.

Common Pitfalls to Avoid

  • Presenting CBT or fixed-increment graded exercise as disease-modifying. Both can worsen PEM; frame CBT only as optional coping support.
  • Dismissing symptoms as purely psychological when PEM/OI features are present.
  • Large medication changes during an acute crash—prefer “start low, go slow”.

Diagnosis Code

ICD-10-CM Code: G93.32

Description: Myalgic encephalomyelitis/chronic fatigue syndrome

Use this code for patients meeting IOM/NAM 2015 diagnostic criteria. Avoid older or nonspecific codes such as G93.3 (postviral fatigue syndrome) unless clearly indicated.

Notes

  • Use targeted testing to exclude common mimics and establish baselines.
  • Consider formal tilt-table testing if bedside measures are inconclusive but suspicion for OI remains high.

Documentation (Examples)

Assessment

Chronic multisystem illness consistent with ME/CFS. Hallmark PEM present; symptoms include unrefreshing sleep, cognitive dysfunction, and OI features. Lying→standing vitals show [results]. Rule-outs initiated per guideline.

Plan

Education on PEM/pacing; avoid exertion that provokes crashes. OI measures (fluids/salt/compression ± meds as appropriate). Sleep optimization and targeted symptom relief. Follow-up in 4–6 weeks with written crash-prevention plan.

For health professionals. Informational only — not medical advice. Based on IOM/NAM 2015 criteria and common clinical practices.