The chronic fatigue syndrome has become the fin de siècle illness, now getting similar attention to that of neurasthenia, which dominated medical thinking at the turn of the century. Myalgic encephalomyelitis was an early term introduced in the United Kingdom in 1957 for this state, but it had little or no public or professional prominence. Until then "chronic fatigue had become invisible", with "no name, no known etiology, no case illustrations or clinical accounts in the medical textbook, no ongoing research activity -- nothing to relate it to current medical knowledge". The reconstruction of chronic fatigue began in the mid-1980s, with the emergence of "chronic Epstein-Barr virus syndrome", which was later converted to chronic fatigue syndrome. The former term, which first emerged in the mid-1980s, is now regarded as a misnomer and should be abandoned. In the popular American literature the term "chronic fatigue and immune deficiency syndrome" is preferred by the most active of the patient lobbies, while myalgic encephalomyelitis continues to be the usual label in the United Kingdom. The relevant research linking chronic fatigue syndrome with somatization is reviewed in this article. Understanding the nature of somatization can still shed some light on the meaning of chronic fatigue at the end of the 20th century.

Key terms immune deficiency; myalgic encephalitis