AKT · Neurology/Cord & peripheral

ME/CFS (myalgic encephalomyelitis / chronic fatigue syndrome)

Not established; often post-infective onset

Overview

A chronic, disabling multi-system condition whose cardinal feature is post-exertional malaise — a disproportionate worsening of symptoms after activity, typically delayed by hours to days and taking a disproportionately long time to recover from. NICE NG206 (2021) reframed both the diagnosis and the management substantially.

Recognise

Post-exertional malaise — the cardinal feature, delayed in onset and disproportionate in severity and duration
Debilitating fatigue not relieved by rest and not the result of ongoing exertion
Unrefreshing sleep, or a disturbed sleep–wake cycle
Cognitive difficulty ("brain fog") — slowed processing, word-finding, poor working memory
Frequently orthostatic intolerance, pain, and sensory hypersensitivity
Often follows an infection; severity ranges from mild to severe (housebound or bedbound)

Red flags

Weight loss, lymphadenopathy, focal neurology, synovitis or abnormal screening bloods → these are NOT ME/CFS; investigate for another cause

Differentials & how to tell them apart

HypothyroidismRaised TSH with cold intolerance, weight gain and slow-relaxing reflexes

Anaemia / iron deficiencyLow haemoglobin or ferritin — corrects with treatment

DepressionAnhedonia and low mood dominate; exercise typically IMPROVES symptoms, whereas in ME/CFS it worsens them for days

Obstructive sleep apnoeaSnoring, witnessed apnoeas, daytime somnolence with a high Epworth score

Coeliac diseasePositive tissue transglutaminase antibodies, often with GI symptoms or iron deficiency

FibromyalgiaWidespread pain dominates over fatigue; the two overlap and can coexist

Investigations

There is no diagnostic test — the diagnosis is clinical, made on the symptom pattern with normal investigations. Screen to exclude alternatives: FBC, U&E, LFT, TFT, calcium, glucose/HbA1c, CRP/ESR, ferritin, coeliac serology, creatine kinase, and urinalysis. Add others only where the history points to them. NICE advises suspecting ME/CFS from 6 weeks of symptoms in adults and CONFIRMING the diagnosis at 3 months — a change from previous guidance, which required longer.

Management

Energy management within the patient's own limits, plus treatment of symptoms — sleep, pain and orthostatic intolerance

1Suspect at 6 weeks; exclude alternatives with the screening bloods; confirm the diagnosis at 3 months. Do not delay support while waiting to confirm — access to care should not depend on the label.
2Energy management ("pacing"): the patient establishes their own sustainable energy envelope and stays within it, with the flare-up plan agreed in advance. Manage sleep, pain and orthostatic symptoms individually.
3Refer to a specialist ME/CFS service. Provide practical support — a care and support plan, workplace or school adjustments, and consideration of benefits and equipment for severe disease.Gate: Severe or very severe disease (housebound or bedbound) → specialist input including home visits, and vigilance for malnutrition

Key points

NICE NG206 (2021) explicitly states that graded exercise therapy — fixed incremental increases in physical activity — should NOT be offered, and that CBT may be offered to support coping but is not a cure and should not be presented as one. Recommending a graded exercise programme is now a guideline error, and knowing that is the point of the topic.

Monitor & prognosis

Regular review of the care and support plan, with attention to nutrition in severe disease.

Variable. Full recovery in adults is uncommon; many improve or stabilise, and children and young people do better. Prolonged relapses commonly follow over-exertion.

Source: NICE NG206 — myalgic encephalomyelitis/chronic fatigue syndrome (2021)