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What is M.E.?

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Diagnosis

Diagnosis

There is currently no specific test that can detect M.E. Potential biomarkers – a characteristic by which a particular biological process or disease can be identified – are still being investigated.

M.E. is instead diagnosed by excluding other illnesses that share the same symptoms, This should be a positive clinical diagnosis made on a well-characterised constellation of symptoms.

The earlier the illness is recognised, the sooner symptom management and support can begin. Many people with M.E. find it helps to keep a diary of their symptoms so that they can take this to their GP.

Once you have a diagnosis of M.E. your GP may be able to refer you to an M.E. specialist (subject to availability in your area) who will be able to work with you on ways of managing your symptoms. Most specialist clinics don't accept self-referrals so it's important that you get a diagnosis if you'd like to see an M.E. specialist. 

You can find out more about diagnosis and questions to ask GPs in our Newly diagnosed with M.E. booklet. 

Diagnostic criteria

No single set of diagnostic criteria (a specific combination of signs, symptoms, and test results used to determine the correct diagnosis) for M.E. has been universally agreed.

Instead, there are different classifications used in different countries and sometimes within the same country for diagnosing the illness. This means that different groupings of symptoms might be required.

Speaking at the UK CFS/M.E. Research Collaborative conference in 2014, Professor Andrew Lloyd advised being “very clear about the purpose of the criteria. From the point of view of making a diagnosis, the criteria broadly matter but actually what really matters is the care that leads from the diagnosis.”

This was a completely different issue for criteria for entry into a clinical trial or a research study, he said, where it was important to understand the similarities and differences within the disorder.


NICE guideline

In 2007, the National Institute for Health and Care Excellence (NICE) published a clinical guideline on the diagnosis and management of M.E. for NHS healthcare professionals in England and Wales.

The NICE guideline for M.E. states that a diagnosis should be made after other possible diagnoses have been excluded and the symptoms have persisted for:

  • four months in an adult
  • three months in a child or young person; the diagnosis should be made or confirmed by a paediatrician.

It also says that a diagnosis of M.E. should be reconsidered if none of the following key features are present:

  • post-exertional fatigue or malaise
  • cognitive difficulties
  • sleep disturbance
  • chronic pain.

Scottish Good Practice Statement

Produced in 2010, the Scottish Good Practice Statement (SGPS) on M.E. provides GPs with guidance on the differential diagnosis and clinical management of patients with M.E.  

The SGPS recommends:

  • making a formal positive diagnosis three-four months into the illness, based on symptom pattern (see below), and excluding other conditions as appropriate
  • making a full physical examination
  • making a full mental state examination to identify patients with reversible co-morbid disorders
  • asking about recent travel, tick/insect bites, unusual infections and drug/ alcohol use
  • reviewing current medication
  • ordering tests including full blood count, urea, electrolytes and creatinine, liver function thyroid function, glucose, erythrocyte sedimentation rate
  • C-reactive protein, calcium, creatine kinase, ferritin and urinalysis (see p 8-9 of the SGPS for a full list).

Misdiagnosis of M.E.

An evaluation (White et al, 2012, Journal of the Royal Society of Medicine short reports) of referrals made by GPs to the specialist clinic at Bart’s Hospital found that 49% did not have a diagnosis of M.E.

A study (Newton et al, 2010, Journal of the Royal College of Physicians of Edinburgh) of patients referred by GPs to the Newcastle NHS M.E. Service found that 40% were diagnosed with conditions other than M.E. Of these:

  • 47% were found to have fatigue associated with a chronic disease, including metabolic syndrome, neurological disorder, connective tissue disorder/ autoimmune disease and fibromyalgia
  • 20% had a primary sleep disorder
  • 15% had a psychological/psychiatric illnesses, most commonly depression, anxiety and post-traumatic stress disorder
  • 13% of patients had fatigue for which the cause remained unexplained
  • 4% had cardiovascular disorders.