CCC Criteria for ME/CFS (2003)


Carruthers BM, Jain, AK, De Meirleir KL, Peterson DL, Klimas NG, Lerner AM, Bested AC, Henry PF, Joshi P, Powles ACP, Sherkey JA, van de Sande M. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment Protocols. Journal of Chronic Fatigue Syndrome, Vol. 11(1), 2003.


Read the Article

Read the Practitioner Guidelines


Clinical Working Case Definition of ME/CFS


A patient with ME/CFS will meet the criteria for fatigue, post-exertional malaise and/or fatigue, sleep dysfunction, and pain; have two or more neurological/cognitive manifestations and one or more symptoms from two or more of the categories of autonomic, neuroendocrine and immune manifestations; and adhere to item 7.


1. The patient must have a significant degree of new onset, unexplained, persistent or recurrent physical and mental fatigue that substantially reduces activity level.


2. Post-Exertional Malaise and/or Fatigue: There is an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability, post-exertional malaise and/or fatigue and/or pain and a tendency for other associated symptoms within the patient’s cluster of symptoms to worsen. There is a pathologically slow recovery period — usually 24 hours or longer.


3. Sleep Dysfunction: There is unrefreshed sleep or sleep quantity or rhythm disturbances such as reversed or chronic diurnal sleep rhythms.


4. There is a significant degree of myalgia. Pain can be experienced in the muscles and/or joints, and is often widespread and migratory in nature. Often there are significant headaches of new type, pattern or severity.


5. Neurological/Cognitive Manifestations: Two or more of the following difficulties should be present: confusion, impairment of concentration and short-term memory consolidation, disorientation, difficulty with information processing, categorizing and word retrieval, and perceptual and sensory disturbances — e.g. spatial instability and disorientation and inability to focus vision. Ataxia, muscle weakness and fasciculations are common. There may be overload phenomena: cognitive, sensory — e.g. photophobia and hypersensitivity to noise — and/or emotional overload, which may lead to “crash” periods and/or anxiety.


6. At least one symptom from two of the following categories:

a.  Autonomic Manifestations: orthostatic intolerance (neurally mediated hypotension (NMH), postural orthostatic tachycardia syndrome (POTS), delayed postural hypotension); light-headedness; extreme pallor; nausea and irritable bowel syndrome; urinary frequency and bladder dysfunction; palpitations with or without cardiac arrrhythmias; exertional dyspnea.

b. Neuroendocrine Manifestations: loss of thermostatic stability (subnormal body temperature and marked diurnal fluctuation, sweating episodes, recurrent feelings of feverishness and cold extremities); intolerance of extremes of heat and cold; marked weight change (anorexia or abnormal appetite); loss of adaptability and worsening of symptoms with stress.

c. Immune Manifestations: tender lymph nodes; recurrent sore throat; recurrent flu-like symptoms; general malaise; new sensitivities to food, medications and/or chemicals.


7. The illness persists for at least six months. It usually has a distinct onset, although it may be gradual. Preliminary diagnosis may be possible earlier. Three months is appropriate for children.


Information on this website is presented by Paradigm Change. Links are in orange (no underlining).