[Does fibromyalgia exist?].

The term fibromyalgia, though often used, is not justified since no fibrosis has been shown on the histological level. The aim of this article is to make a critical analysis of the semiology usually attributed to fibromyalgias, to cite the main related syndromes whose nosology is often unclear (benign myalgic encephalomyelitis, epidemic neuromyasthenia, diffuse idiopathic multifocal pain syndrome, chronic fatigue, AMP desaminase deficiency, etc.), to prefer the purely descriptive term of "persistent, diffuse myalgia with no recognized organic etiology". According to the author's experience, a psychological etiology is detectable in only 25% of the cases. Morphological or functional muscular abnormalities are sometimes found, but their significance is not well known. A real multifactorial vicious circle partly explains the physiopathological complexity.