Diagnostic Criteria Chronic fatigue syndrome-the CDC definition (1988)

The first formal case definition included two major criteria along with the following minor criteria: 6 or more of the symptom criteria listed below and 2 or more of the physical criteria; or 8 or more symptom criteria.

Major criteria: 

1. New onset of persistent or relapsing, debilitating fatigue or easy fatigability in a person who has no previous history of similar symptoms, that does not resolve with bed rest, and that is severe enough to reduce or impair average daily activity below 50 percent of the patient’s premorbid activity level for a period of at least 6 months  
2. Exclusion of other clinical conditions that may produce similar symptoms (e.g., malignancy, autoimmune disease, chronic psychiatric disease, and chronic inflammatory disease, among others)

Minor criteria:Symptom criteria

1. Mild fever  
2. Sore throat  
3. Painful lymph nodes in the anterior or posterior cervical or axillary distribution  
4. Unexplained generalized muscle weakness  
5. Muscle discomfort or myalgia  
6. Prolonged ( ≥ 24 hours) generalized fatigue after exercise  
7. Generalized headaches  
8. Migratory arthralgia without joint swelling or redness  
9.  Neuropsychologic complaints
10.  Sleep disturbance

Physical criteria  

1. Low-grade fever  
2.  Nonexudative pharyngitis

Source: Holmes, G.P., Kaplan, J.E., Nelson, M.G., Komaroff, A.L., Schonberger, L.B., Straus, S.E., et al. (1988). Chronic fatigue syndrome: A working case definition.  Annals of Internal Medicine, 108, 387-389.