Overestimation and Underestimation of Fibromyalgia: Clinical Reflections, Diagnostic Limitations, and Psychological Implications

Over the last thirty years, fibromyalgia has shifted from a relatively unrecognized condition to a widely diagnosed syndrome. Prevalence estimates in Western countries range from 2% to 4%, yet a debate is growing about the possibility that its actual prevalence is partly overestimated. This article examines the main factors contributing to possible overdiagnosis – the evolution of ACR criteria (1990, 2010, 2016), the absence of specific biological markers, the overlap with psychological and functional disorders, and the role of psychological and cultural factors – and, in parallel, documents the corresponding and equally relevant phenomenon of underdiagnosis and misclassification. The clinical consequences of both phenomena are discussed – medicalization and the development of a chronic illness identity on the one hand, diagnostic delay, invalidation, and worsened outcomes on the other – together with the need for a multidimensional diagnostic approach integrating rheumatology, neurology, clinical psychology, and pain medicine. Recognizing the diagnostic complexity of fibromyalgia does not mean denying patients' suffering, but promoting a more accurate diagnosis and an integrated understanding of the relationship between mind, body, and trauma.