Table 2

 Adult criteria for diagnosis of chronic fatigue syndrome/myalgic encephalopathy (CFS/ME)2

• Debilitating persistent or relapsing fatigue for at least 6 months which is not life long and is severe enough to cause substantial reduction in previous levels of occupational, educational, social, or personal activities
• Not the result of ongoing exertion and not substantially alleviated by rest
• Four or more of the following symptoms persisting or recurring during 6 or more consecutive months of illness and did not predate the fatigue: impaired memory or concentration, sore throat, tender lymph nodes (symptom), muscle pain, pain in several joints without swelling or redness, headache, unrefreshing sleep, feeling ill after exertion
• No clinical evidence of other causes of fatigue