Undiagnosed or Chronic Fatigue Syndrome
From Expert System: Chronic Fatigue
Some undiagnosed cases of chronic and severe fatigue have been grouped under the diagnosis of "Chronic Fatigue Syndrome" (CSF). This rare condition of unknown cause with a prevalence of approximately 37 cases per 100,000 population, is a frequently over-diagnosed cause of fatigue or weakness, and is often confused with psychogenic causes, such as depression. Chronic Fatigue Syndrome is usually a diagnosis made only after excluding other organic conditions. Typical criteria for the diagnosis includes persistent or relapsing SEVERE fatigueor exhaustion for over 6 months duration, reduction of normal daily activity by more than 50%, and failure to resolve with bed rest.
Other diagnostic findings are non-specific and include, among others, mild fever, painful lymph nodes, headaches, sore throat, generalized muscle weakness and muscle discomfort (myalgia). Severe fatigue can persist up to 24 hours after exercise. True Chronic Fatigue Syndrome ("CFS") sometimes comes on as a continuation of "post viral syndrome," which fails to improve or regress with time. Depression may masquerade as CFS or undiagnosed "fatigue." Profound fatigue not improved by bed rest and that may be worsened by physical or mental activity is a hallmark. Symptoms may include impaired memory and/or mental concentration.