Chronic fatigue syndrome (CFS) is also called myalgic encephalomyelitis (ME). It is a challenge to physicians both to diagnosis and treat. It is believed the prevalence is approximately 1% in the general population.
The cause of ME/CFS is unknown. Its mechanism of causing disease is also unknown. It is actually an independent unique disease. No two patients have the same type of symptoms and the associated circumstances vary among individuals. In addition, there was no consistent diagnostic criteria. Over the last 30 years, diagnostic criteria have continuously changed. This is because, as mentioned, there are no unique features of the disease that make for a set pattern.