guidelines

me/cfs (myalgic encephalomyelitis/chronic fatigue syndrome)

detailed summary of nice ng206: recognising me/cfs, excluding alternative diagnoses, and management principles (including post-exertional malaise).

last reviewed: 2026-02-13
based on: NICE NG206: ME/CFS (diagnosis and management). Accessed Feb 2026.
reviewer: Dr Kola Tytler MBBS CertHE MBA MRCGP
view official NICE source

Executive summary

  • Key discriminant feature: post-exertional malaise (PEM) — symptom flare after physical/cognitive/emotional exertion, often delayed and prolonged.
  • Think of ME/CFS early in persistent disabling fatigue with PEM, cognitive dysfunction (“brain fog”), unrefreshing sleep, and activity intolerance.
  • Exclude other causes with a targeted history/exam and baseline tests (anaemia, thyroid disease, diabetes, inflammatory disease, infection, sleep apnoea, mood disorders, medication effects).
  • Management is supportive and structured: shared plan, energy management/pacing, symptom treatment, and reasonable adjustments (work/education).
  • Avoid outdated framing: do not push fixed incremental exercise programmes that ignore PEM; activity advice must be personalised and PEM-aware.
  • Comorbidity is common: orthostatic intolerance, pain syndromes, migraine, IBS, anxiety/depression; treat what is treatable.

Assessment and baseline evaluation

  • History: onset (post-viral?), fatigue pattern, PEM details (what triggers it, latency, duration), sleep quality, cognition, pain, orthostatic symptoms (lightheadedness, palpitations), GI symptoms.
  • Functional impact: ability to work/study, ADLs, mobility, “good days vs bad days”, and post-activity crashes.
  • Red flags / alternative diagnoses: weight loss, fevers/night sweats, focal neurology, inflammatory joint symptoms, exertional chest pain/syncope, progressive focal weakness.
  • Baseline tests (typical): FBC, ferritin/B12/folate if indicated, U&E, LFT, CRP/ESR, TFTs, HbA1c/glucose, coeliac screen if GI features, CK if myopathy features, and others guided by history.
  • Consider sleep disorders: screen for OSA (snoring, witnessed apnoea, daytime somnolence) and restless legs.

Diagnosis framing (how to explain it clearly)

  • Validate symptoms and explain that ME/CFS is a recognised condition characterised by exertion intolerance (PEM), not “ordinary tiredness”.
  • Use a shared model: the body’s “energy envelope” is reduced; exceeding it triggers PEM, which can set recovery back.
  • Set expectations: improvement can be slow and non-linear; the aim is stabilisation, fewer PEM episodes, and gradual functional gains where possible.
  • Document comorbidities and treat them actively (e.g., migraine, IBS, anxiety, orthostatic intolerance).

Management in primary care (PEM-aware, practical)

  • Energy management (“pacing”): identify triggers, plan rest, break tasks into smaller units, and aim to avoid repeated PEM cycles.
  • Symptom-focused care: sleep support, pain management, nausea/GI management, headache pathways, and orthostatic advice (hydration, salt where appropriate, compression garments in selected patients).
  • Reasonable adjustments: work/education accommodations, phased return only if PEM is controlled, and written evidence for occupational health/benefits where needed.
  • Referral: consider specialist ME/CFS services where available (multidisciplinary input; activity guidance and rehabilitation should be PEM-aware).
  • Mental health support: address secondary anxiety/depression; psychological support can help coping and quality of life (not as “the cause”).

Frequently asked questions

What differentiates ME/CFS from “being run down” or depression?
PEM is the high-yield differentiator: worsening after exertion, often delayed and prolonged. Mood symptoms can coexist, but PEM and exertion intolerance point strongly toward ME/CFS.
Should I recommend graded exercise therapy?
Avoid one-size-fits-all incremental exercise programmes that ignore PEM. Activity advice should be personalised, stabilisation-focused, and PEM-aware.
What is the most useful early intervention in primary care?
Education on PEM and pacing/energy management, plus active management of comorbid symptoms and sleep. This can prevent repeated “boom–bust” cycles.
Which tests are most important initially?
A sensible exclusion screen (FBC, U&E, LFT, CRP/ESR, TFTs, glucose/HbA1c, ferritin/B12/folate as indicated) and targeted tests guided by symptoms.
How do I counsel about prognosis?
Be realistic: improvement is often gradual and variable. The goal is reducing PEM frequency/severity and improving function with a personalised plan.

Transparency

This page is an educational, clinician-written summary of publicly available NICE guidance intended for trained healthcare professionals. It uses original wording (not copied text) and should be used alongside the full NICE source, local pathways, and clinical judgement. Doses provided are for general reference; always check the BNF/SPC.