Diagnostic Criteria for Chronic Fatigue Syndrome  


Major Criteria 
1. New onset of fatigue lasting longer than six months with 50 percent reduction in activity 
2. No other medical or psychiatric conditions that could cause the symptoms 

Minor Criteria Symptoms must begin at or after onset of fatigue 

1. Low-grade fever
2. Sore throat
3. Painful lymph nodes
4. Generalized muscle weakness 
5. Muscle pain
6. Prolonged fatigue after exercise
7. Headaches
8. Joint pain
9. Sleep disturbance
10.Neuropsychologic complaints, such as forgetfulness, confusion, difficulty concentrating, depression
11.Acute onset (over a few hours to a few days) 

Physical Criteria 

1.Low-grade fever
2. Throat inflammation
3. Palpable or tender lymph nodes