How To - Diagnosing Chronic Fatigue Syndrome (ME/CFS)

A guide to diagnosing ME/CFS from Health Rising's "How To" project

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    Diagnostic issues have plagued chronic fatigue syndrome (ME/CFS) for decades. Because like fibromyalgia, ME/CFS is diagnosed using symptoms (and by ruling out other diseases)

    Over time the criteria have ranged from the simplistic (Oxford) to the vague (Fukuda) to the complex (Canadian Consensus Criteria and International Consensus Criteria).

    Diagnostic Algorithm From IOM Report (2015)

    A 2015 NIH funded report from the prestigious Institute of Medicine providing new criteria which has, for the time being at least, changed all that. Recognizing the primary care doctors need to be able to easily assess ME/CFS patients it came up with an up to date but simple diagnostic guideline for ME/CFS.

    The new criteria focuses on four symptoms: fatigue, postexertional malaise, sleep issues and cognition and/or orthostatic intolerance.
    • Proposed-Diagnostic-Criteria (HTML)
    • Diagnostic Algorithm (HTML)
    Check out Dr. Alison Bested's "How to Make the Diagnosis" Primer for physicians and Health Rising's "Do I Have Chronic Fatigue Syndrome (ME/CFS)? page.

    A Little History

    The 1994 Fukuda research definition produced by the CDC masqueraded as a clinical definition for decades. The Canadian and International Consensus Criteria produced by ME/CFS experts highlighted post-exertional malaise as the key symptom in ME/CFS but were too cumbersome and complex to get traction in the mainstream medical community.

    In 2015, after a year of work, the ME/CFS experts in an Institute of Medicine report produced a definition that was both accurate and easy to understand.

    Older Criteria
    • Canadian Consensus Criteria (2003) - older, more complex diagnostic criteria created by ME/CFS experts. This seminal work brought post-exertional malaise to the fore and paved the way for that symptom to gain traction. Still provides excellent overview of ME/CFS symptoms and characteristics
    • International Consensus Criteria (2011) - updated version of Canadian Consensus Criteria created by 25 ME/CFS experts. Removes six-month waiting period for diagnosis. Highlights postexertional neuroimmune exhaustion (PENE). Identifies neurological impairments, neurocognitive problems, pain, sleep, etc. issues in ME.
    • The Fukuda Criteria (1994) - Developed by the CDC in conjunction with a group of ME/CFS experts, the Fukuda criteria was the only research definition used for ME/CFS for over twenty years. that ended up being used as a clinical definition as well for many years. Widely criticized for not requiring post-exertional malaise, the Fukuda definition morphed into a clinical definition as well. The Fukuda definition is no longer considered an acceptable research or clinical definition.
    • Oxford Criteria (1991) - is a very broad criteria produced by a group of United Kingdom psychiatrists which has been commonly used in UK and European CBT/GET studies. The Oxford criteria were debunked in the Institute of Medicine report because of their tendency to allow people with depression (but not ME/CFS) to be classified as having ME/CFS. The criteria have been called severely “flawed", were suspected of causing “harm". The Agency for Healthcare Research and Quality had so little faith in the Oxford criteria that they removed it from their CBT/GET study analyses. When they did so they found very little evidence for CBT/GET efficacy in ME/CFS).
    • CDC Website - provides very basic overview of ME/CFS diagnosis -
    Technical Papers

    • DePaul Symptom Questionnaire - Symptom questionnaire incorporating frequency and severity often used in ME/CFS studies; developed by Leonard Jason PhD and the Chronic Fatigue Syndrome Project at DePaul University, Chicago.
    • Myalgic Encephalomyelitis - Leonard Jason PhD makes the case for a simple core definition for Myalgic Encephalomyelitis (ME/CFS) followed by subtyping.

    Comorbid Diseases

    Some people with chronic fatigue syndrome (ME/CFS) also have one or more comorbid diseases that commonly occur with it.

    The list of possible comorbid diseases is a long one and includes

    ME/CFS Mimics