Chronic Fatigue Syndrome, also known as Myalgic Encephalopathy, Post Viral Fatigue Syndrome, Chronic Fatigue and Immune Dysfunction Syndrome, is a poorly understood condition that is characterised by profound fatigue and exhaustion, loss of muscle power, pain and tenderness following normal physical or mental activity and a range of neurological, endocrine and cognitive disturbances. CFS is classified as a neurological disorder by the World Health Organisation (International Classification of Disease 10: G93.3).
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