Understanding Myalgic Encephalomyelitis (ME) Criteria
ME International does not recognize CFS-Fukuda, ME/CFS-CCC, or ME-CFS-SEID (aka IOM/NAM report) as an accurate diagnosis for ME.
Criteria Comparison
- Multiple Criteria Comparison (from Open Medicine Foundation)
Covers Holmes, Oxford, Fukuda, Canadian Consensus, NICE 2007, International Consensus, IOM & NICE 2021.
NOTE: IOM (NAM) criteria, originally labeled SEID, took over the ME/CFS label and was posted on the CDC website since at least 2018. - CFS vs. M.E.
‘CFS’ and M.E. comparison chart. This chart illustrates the many differences between Chronic Fatigue Syndrome (CFS) and Myalgic Encephalomyelitis (M.E.). As this chart shows, despite what many groups claim, CFS and M.E. are not the same. - ME-ICC vs ME/CFS-SEID (pdf)
Compares criteria between ME as per the ICC and ME/CFS-SEID as per the IOM report.
Does everyone with CFS (as defined by Fukuda) have ME?
In a 2023 study, it was found that “… Almost 90% of the participants fulfilled the Fukuda case definition, compared to 80%, 59% and 39% fulfilling the IOM, CCC and ME-ICC case definitions, respectively.”

MEI’s Myalgic Encephalomyelitis – Understanding Diagnosis
(20:37 long video)
This video discusses the history of ME, the lived experience, including recognition of the most severe patients, a full description of how to diagnose using the International Consensus Criteria as well as the challenges of getting a diagnosis. Proper diagnosis is vital for patients to get proper treatment.
ME-ICC: International Consensus [research] Criteria – 2011 Link
en Español in het Nederlands
ME-Hyde: Dr. Byron Hyde – enteroviruses – 2007/updated 2016 Link
ME/CFS-CCC: Canadian Consensus [clinical] Criteria (CCC)- 2003 Link
ME-Ramsay: Ramsay case description – 1981 Link
Audio file of Dr. Ramsay explaining his findings (1988)
LINK on the Royal Free 1955 Twitter account – @RFH1955
Articles which reference Dr. Ramsay
Getting an ME Diagnosis using the ICC
The ME-ICC questionnaire from www.MEadvocacy.org/resources is a useful tool to understand if ME is a reasonable diagnosis to consider. Circling the symptoms and presenting this to your doctor (and family/friends) can help simplify the challenge of explaining the breadth/depth of ME.
“Do I fit the ICC?”: English en Español
The next step is to confirm the ME diagnosis. The IC Primer guides doctors to diagnose, treat and rule out other diseases.
The ICC alone is not enough to confirm an ME diagnosis. See an easy-to-read 2-page Dr. handout regarding the IC Primer HERE.
On 01 January 2022, the World Health Organization’s (WHO’s) International Classification of Diseases code (ICD-11) for ME of 8E49 went into effect. Some countries will individually move to ICCD 11 on their own time table. In the U.S., the ICD diagnosis code for ME is G93.32 as of 01 October 2022 . Note: Combining different patient groups under one label (such as ME/CFS) leads to inadequate treatments for #pwME.
HERE’s a good explanation (pdf) from Suzy Chapman, Dx Revision Watch about the ICD coding of PVFS, ME and CFS as of November 2019. (6/19/20)
ME vs. CFS – THEY’RE NOT THE SAME! 31 January 2014
Even though this was written in 2014, this explanation of ME and CFS by Documenting M.E. is still valid and pertinent.
Review of case definitions for ME/CFS 29 July 2020
Lim and Son (Republic of Korea)
This paper gives a good history of the 25 case definitions/diagnostic criteria created since 1986, based on three conceptual factors (etiology, pathophysiology, and exclusionary disorders). ~ MEI
“…ME/CFS has been named differently (e.g., postviral fatigue syndrome, neurasthenia) depending on the perspectives of the researchers; likewise, diagnostic criteria or case definitions have also been changed accordingly.” Conclusions: “In this review, we found three key factors that have affected ME/CFS case definitions: etiology, pathophysiology, and exclusionary disorders. These factors have impacted the specification of the main symptoms, required conditions, and range of inclusive and exclusive symptoms/disorders in the development of case definitions.” – 29 July 20
Chronic Fatigue Syndrome (CFS) and Other Criteria
NICE (UK) Guideline [NG206] (Based on ME/CFS-SEID) 29 October 2021
“This guideline covers diagnosing and managing myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome (ME/CFS) in children, young people and adults. It aims to improve awareness and understanding about ME/CFS and when to suspect it, so that people are diagnosed earlier. It includes recommendations on diagnosis, assessment and care planning, safeguarding, access to care and managing ME/CFS and its symptoms.” – 29 October 2021
Chronic Fatigue Syndrome: A Working Case Definition 01 March 1988
Holmes, Gantz, Komaroff, Schonberger, Straus, Jones, Dubois, Cunningham-Rundles & Pahwa et al (U.S.)
CFS was never intended to be seen or treated as one specific illness, but was created as a category for researching unexplained fatigue. ~ MEI
“We propose a new name for the chronic Epstein-Barr virus syndrome—the chronic fatigue syndrome—that more accurately describes this symptom complex as a syndrome of unknown cause characterized primarily by chronic fatigue. We also present a working definition for the chronic fatigue syndrome designed to improve the comparability and reproducibility of clinical research and epidemiologic studies, and to provide a rational basis for evaluating patients who have chronic fatigue of undetermined cause.”
Due to decades of misinformation about diagnosing ME, we suggest everyone diagnosed with ME, CFS, ME/CFS-CCC, or systemic exertion intolerance disease (SEID) (and similar diseases) research which criteria most closely matches their experience.
ME/CFS-SEID: Systemic Exertion Intolerance Disease – Beyond ME/CFS IOM Report – 2015 Link
CFS-Reeves: Empirical – 2005 Link
CFS-Fukuda: Fukuda – 1994 Link
CFS-Oxford: UK criteria – 1991 Link
CFS-Holmes: Original CFS description – 1988 Link
Understanding ME/CFS-SEID
Download a chart (pdf) showing a
COMPARISON BETWEEN ME-ICC & ME/CFS-SEID (IOM)
For background on ME/CFS-SEID, see MEadvocacy.org blog “Analysis of CFSAC August 2015 Recommendations for the IOM Criteria”
Note: CDC did not act on CFSAC recommendations.
“Curtain dropped” on CFSAC Sept. 2018.
MEadvocacy.org resources page contains handouts and more information.