Chronic Fatigue Syndrome (CFS) is a debilitating condition of persisting or relapsing fatigue with a prevalence of 0.5% in the U.K (White and Clare, 2002, p1234). In the past, research in this area has been fraught with difficulty due to vague and inconsistent diagnostic criteria. However, more recently the Center for Disease Control and Prevention (CDCP) in the United States has produced a standardised framework for a diagnosis of chronic fatigue.
The patient must have severe and disabling fatigue for a minimum of six months duration associated with a decrease of at least 50% in functioning and with at least four of the following eight symptoms being concurrently present over the same period
Enlarged and tender axillary/cervical lymph nodes | Recurrent sore throats | New headaches | Unrefreshing sleep | Arthralgia | Myalgia | Post-exertional malaise | Neuropsychological disturbance
Fatigue that can be explained by any medical condition precludes a diagnosis of CFS and this criteria does help to make distinctions from Epstein-Barr (Scott and Dinan, 1999, p3). However, this criterion could be considered a somewhat narrow view of a multifactorial syndrome in which a sufferer can be present with any of a wide range of symptoms alongside the persisting fatigue. Various other symptoms, including palpitations, arrhythmias and nausea, are not included and there is much overlap with fibromyalgia. Whether this criterion has been recently used to assess the prevalence in the UK is unclear.