Fatigue Syndrome, Chronic

**Definition:** A syndrome characterized by persistent or recurrent fatigue, diffuse musculoskeletal pain, sleep disturbances, and subjective cognitive impairment of 6 months duration or longer. Symptoms are not caused by ongoing exertion; are not relieved by rest; and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Minor alterations of immune, neuroendocrine, and autonomic function may be associated with this syndrome. There is also considerable overlap between this condition and FIBROMYALGIA. (From Semin Neurol 1998;18(2):237-42; Ann Intern Med 1994 Dec 15;121(12): 953-9)

**Tree numbers:** - C05.651.310 - C10.586.500.600 - C10.668.364 - C23.550.291.500.392

**Synonyms:** - Chronic Fatigue-Fibromyalgia Syndrome - Infectious Mononucleosis-Like Syndrome, Chronic - Royal Free Disease - Chronic Fatigue and Immune Dysfunction Syndrome - Chronic Fatigue Disorder - Systemic Exertion Intolerance Disease - Myalgic Encephalomyelitis - Encephalomyelitis, Myalgic - Chronic Fatigue Syndrome - Postviral Fatigue Syndrome