Myalgic Encephalomyelitis / Chronic Fatigue Syndrome


This guideline applies to children and adults.



ME/CFS is a relatively common condition, estimated to affect over 250,000 people in England and Wales, with about 2.4 times as many women affected as men1. Typically, there is a viral event that pre-dates the development of a complex, chronic medical condition that affects multiple body systems. Diagnosis is clinical, and mildly affected patients might be managed in primary care where a close doctor-patient relationship is key.


Red Flag Features

  • Fatigue associated with other medical conditions e.g. stroke, multiple sclerosis, cancer etc.
  • Chronic widespread pain, in absence of fatigue or other symptoms

These features are not suggestive of ME/CFS and are therefore exclusions to referral.


Key Features of Assessment

Features supportive of a diagnosis of ME/CFS include:

4 major criteria:

  1. Debilitating fatigue worsened by activity.
  2. Post-exertional malaise
  3. Unrefreshing sleep or sleep disturbance or both
  4. Cognitive difficulties

In the absence of other causes, non-specific symptoms may include:

Orthostatic intolerance, autonomic dysfunction, temperature hypersensitivity, neuromuscular symptoms, flu-like symptoms, nausea, intolerance to alcohol/foods/chemicals, heightened sensory sensitivities, unexplained pain (headache, sensitivity to touch, eye and abdominal pain).



Required with/prior to referral, within 3 months of onset:

  • Urinalysis
  • Full blood count with differential count
  • C-Reactive Protein (CRP)
  • Biochemisty:
    • Random blood glucose
    • HbA1c
    • Bone profile
    • Urea and electrolytes
    • Creatine kinase
    • Thyroid function tests (and thyroid peroxidase antibodies if TFT abnormal)
    • Liver function tests
    • Coeliac testing
    • Ferritin (if age < 25)


The following tests are not required for referral purposes, but may be useful to exclude other causes of fatigue depending upon clinical discretion:

  • Ferritin (in adults)
  • Vitamin B12, Folate
  • Vitamin D
  • 9am cortisol
  • Serological tests:
    • TB
    • Lyme disease
    • Toxoplasmosis



Once diagnosis of ME/CFS established or suspected:

  • Provide patient information.
  • Advise patients:
    • not to use more energy than they perceive they have, by managing their daily activity and not “pushing through” their symptoms.
    • to rest as needed initially, which might mean making changes to their daily routine, including work/school/home.
    • to avoid daytime naps.
    • to maintain a healthy, balanced diet and adequate fluid intake.
  • Consider prescribing simple analgesia and anti-emetics as required for symptomatic relief.


Advice and Guidance

There is no formal Advice and Guidance service available.

MDT patient discussions are open to health professionals and can be requested via email: rcht.mecfs@nhs.net




Cornwall and Isles of Scilly Specialist ME/CFS Service for children* and adults


Inclusion criteria

Patients aged 16 years and over, registered with a GP in CIOS, where all the following applies:

  • All 4 major criteria are present, lasting a minimum of 6 weeks in adults (or 4 weeks in children*) OR re-occurrence of life-altering symptoms in a previously diagnosed patient.
  • Significantly reduced ability to engage in occupational, social, or personal activities compared to pre-illness levels.
  • History, examination, and investigations do not suggest an alternative diagnosis.


*Children and young adults under the age of 16 years old must be referred to paediatrics first. They can only be referred to the ME/CFS service once they are under the care of a paediatrician.


If patient is a sole carer, or missing significant amounts of time off work or school, consider early referral and document clearly in the referral letter.


Exclusion criteria


Supporting Information

For professionals:

NICE [NG206] – ME/CFS: diagnosis and management

For patients:

NICE [NG206] – ME/CFS, Information for the public




  1. NICE [NG206]: Myalgic encephalomyelitis (or encephalopathy) / chronic fatigue syndrome: diagnosis and management, published 29 October 2021


Page Review Information

Review date

24 May 2024

Next review date

24 May 2026

GP speciality lead

Dr Laura Vines


Carol Wilson, Speciality Lead

Dr Dmitry Pshezhetskiy, Speciality Doctor