NICE ME/CFS diagnostic criteria 2021

The NICE ME/CFS consensus-based diagnostic criteria 2021 or NHS diagnostic criteria 2021 were created by consensus by the NICE ME/CFS Guideline Development Group for use in the NHS in England and Wales.

Suspected ME/CFS criteria

• the person has had all of the persistent symptoms in the box for a minimum of 6 weeks in adults and 4 weeks in children and young people and
• the person's ability to engage in occupational, educational, social or personal activities is significantly reduced from pre‑illness levels and
• symptoms are not explained by another condition.

All the following symptoms are required for suspected ME/CFS:
Debilitating fatigue that is worsened by activity, is not caused by excessive cognitive, physical, emotional or social exertion, and is not significantly relieved by rest.
Post-exertional malaise after activity in which the worsening of symptoms: is often delayed in onset by hours or days is disproportionate to the activity has a prolonged recovery time that may last hours, days, weeks or longer.
Unrefreshing sleep or sleep disturbance (or both), which may include: feeling exhausted, feeling flu-like and stiff on waking broken or shallow sleep, altered sleep pattern or hypersomnia
Cognitive difficulties (sometimes described as 'brain fog'), which may include problems finding words or numbers, difficulty in speaking, slowed responsiveness, short-term memory problems, and difficulty concentrating or multitasking.

Definitions

Activity Any effort that uses energy, which includes cognitive, emotional and social activity as well as physical activity. Different activities combine and interact to cause a cumulative impact for the person. Children and young people Under 18s. Fatigue Fatigue in ME/CFS typically has the following components: feeling flu-like, especially in the early days of the illness restlessness or feeling 'wired but tired' low energy or a lack of physical energy to start or finish activities of daily living and the sensation of being 'physically drained' cognitive fatigue that worsens existing difficulties rapid loss of muscle strength or stamina after starting an activity, causing for example, sudden weakness, clumsiness, lack of coordination, and being unable to repeat physical effort consistently. Post-exertional malaise The worsening of symptoms that can follow minimal cognitive, physical, emotional or social activity, or activity that could previously be tolerated. Symptoms can typically worsen 12 to 48 hours after activity and last for days or even weeks, sometimes leading to a relapse. Post-exertional malaise may also be referred to as post-exertional symptom exacerbation. Unrefreshing sleep Unrefreshing sleep means sleep that is non-restorative. Even after a full night's sleep, people do not feel refreshed. People with ME/CFS often report waking up exhausted and feeling as if they have not slept at all, no matter how long they were asleep.

Diagnostic criteria

No diagnostic test exists but people who meet the suspected ME/CFS criteria should have a number of tests, including urine and blood tests, plus investigations to rule out other causes for the symptoms.

Investigations and tests

• medical assessment (including symptoms and history, comorbidities, overall physical and mental health)
• a physical examination
• an assessment of the impact of symptoms on psychological and social wellbeing
• investigations to exclude other diagnoses, e.g. urine and blood tests

suggested tests
urinalysis for protein, blood and glucose full blood count urea and electrolytes liver function thyroid function erythrocyte sedimentation rate or plasma viscosity C-reactive protein calcium and phosphate HbA1c serum ferritin (blood iron levels) celiac screening creatine kinase

Confirmed ME/CFS

• Investigations and tests must have excluded other possible causes of the symptoms
• Symptoms of suspected ME/CFS in the box below must have been present for at least three months (in adults, children and young people)
  

All the following symptoms are required for a diagnosis of ME/CFS:
Debilitating fatigue that is worsened by activity, is not caused by excessive cognitive, physical, emotional or social exertion, and is not significantly relieved by rest.
Post-exertional malaise after activity in which the worsening of symptoms: is often delayed in onset by hours or days is disproportionate to the activity has a prolonged recovery time that may last hours, days, weeks or longer.
Unrefreshing sleep or sleep disturbance (or both), which may include: feeling exhausted, feeling flu-like and stiff on waking broken or shallow sleep, altered sleep pattern or hypersomnia
Cognitive difficulties (sometimes described as 'brain fog'), which may include problems finding words or numbers, difficulty in speaking, slowed responsiveness, short-term memory problems, and difficulty concentrating or multitasking.
The symptoms persistent for at least three months.

• Adults should be referred to a ME/CFS specialist team to confirm diagnosis
• Children and young people should be referred to a pediatrician for diagnosis

Authors

The NICE Guideline Development Group for ME/CFS (2017-2021) created the NICE ME/CFS (2021) diagnostic criteria.

Guideline Development Group members:

Comparison

Compared to the previous NICE CFS/ME criteria:

• Diagnosis can be earlier - the minimum duration of symptoms is reduced to 3 months
• Post-exertional malaise is a required symptom
• More symptoms are required: four core symptoms, instead of one core symptom and one or more of many optional symptoms
• Many symptoms are no longer diagnostic symptoms including muscle and joint pain, sore throat headaches, nausea, and dizziness: these are recognized as symptoms commonly associated with ME/CFS that may also be found in other conditions

See also

• NICE guidelines
• National Institute for Health and Care Excellence (NICE)
• National Health Service
• Pacing (Energy Management)

Learn more

• ME/CFS NICE guideline [NG206] - guideline website
• ME/CFS:diagnosis and management - NICE guideline (download guideline)