This page introduces the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), offering evidence-based guidance and links to the most accessed professional resources.
Diagnosing & Managing
ME/CFS Diagnostic Criteria
A diagnosis of ME/CFS requires the patient to have three core symptoms:
- Impairment of normal function accompanied by fatigue >6 months
- Post-exertional malaise (PEM)*
- Unrefreshing Sleep*
- Cognitive Impairment*
- Orthostatic Intolerance (OI)
*Must be moderate-to-severe and present >50% of the time
- Cognitive Impairment*
- Orthostatic Intolerance (OI)
*Must be moderate-to-severe and present >50% of the time
Additional Symptoms Supporting Diagnosis
Immune impairment: Acute infection-like onset, susceptibility to infection, perpetual flu-like symptoms, sore throat, tender lymph nodes, fever, new or worsened sensitivities to certain substances (e.g. foods, odors, medications, chemicals). Poor NK cell cytotoxicity (NK cell function, not number) correlates with illness severity in patients and could serve as a biomarker for the severity of the disease.
Neurological impairment: Impaired psychomotor function, muscle weakness, twitching, instability, spatial disorientation, ataxia, sensory changes (e.g. sensitivity or intolerance to light, noise and touch).
Other: Gastrointestinal impairments, genitourinary impairment, neuroendocrine manifestations (e.g. cold extremities, weight change, excessive sweating, high/low temperature, chills/shivers, loss of appetite, alcohol intolerance).
Pain: Headaches, arthralgia, myalgia, other pain symptoms (all highly variable in presence, nature and severity).
Other comoribid conditions may exisit in those with ME/CFS. For more about diagnosis and managment of these common comorbidities see our video series on Unraveling the Complexities of Pain & Fatigue as well as the Long COVID & Post-Viral Syndromes ECHO.
Diagnosing and Managing ME/CFS
U.S. ME/CFS Clinician Coalition
- Testing Recommendations for Suspected ME/CFS (2021)
- ME/CFS Treatment Recommendations (2021)
- Basics of Diagnosis & Treatment (2020)
- Expert Consensus Statements of the U.S. ME/CFS Clinician Coalition (video, 2022)
Mayo Clinic Proceedings
Center for Disease Control (CDC)
Doctors with M.E.
Michigan State Medical Society (1.5 CME credits)
- Long COVID & Post-Viral Syndromes (May 2022)
Long COVID & Fatiguing Illness Recovery Program
- History of ME/CFS (May 2022)
- Register for series
For CME specific to diagnosing and managing ME/CFS and related comorbid conditions, please refer here.
Top Medical Professional Resources
Care Considerations
Orthostatic Intolerance
- 10-Minute NASA Lean Test (passive stand test)
- Orthostatic Intolerance (basics)
- Assessing Orthostatic Intolerance (6 min video)
- Managing Orthostatic Intolerance (5 min video)
Post-Exertional Malaise (PEM)
- Understanding PEM (videos, Doctors with M.E.)
- ME/CFS Crash Survival Guidebook
Pre-visit Forms for Patients
- Good Day/Bad Day Questionnaire (HUA & function)
- Health Assessment Form
Medical Education: Project ECHO
- Long COVID & Post-Viral Syndromes (video, slides)
- Post-Exertional Malaise/PEM (video, slides)
- Part 1: Orthostatic Intolerance Assessment (video, slides)
- Part 2: Managing Orthostatic Intolerance (video, slides)
- Sleep Disturbances/Dysregulation (video, slides)
- Mast Cell Activation Syndrome/MCAS (video, slides)
- Cognitive Impairment (video, slides)
- Anxiety & PTSD (video, slides)
- Chronic Pain (video, slides)
- Post-Viral Gastrointestinal Disruption & Dysfunction (video, slides)
- Pediatric Long COVID (video, slides)
- COVID-19 and Gynecological Health (video, slides)
- What Pathological Changes May Cause the Symptoms of Long COVID (video, slides)
- Headaches in Post-Acute Sequelae of COVID-19 (video, slides)
Note: Live ECHO sessions are reserved for healthcare professionals only. Sessions include: didactic, case presentations and CME.
