The medicalization of normal variants: the case of mitral valve prolapse.

Mild mitral valve prolapse, hypoglycemia, irritable colon, and premenstrual syndrome are examples of anatomico-physiologic phenomena that largely overlap with normal. Such "overlap syndromes" become labeled disease entities by the medical community through a process called medicalization. This report uses mitral valve prolapse (MVP) to exemplify the effects of medicalization on patients, physicians, and society. Ascertainment bias and insufficient controlled clinical studies have led to the description of a clinical entity replete with false associations (e.g., mitral valve prolapse syndrome) and overly pessimistic prognostication (e.g., risk of sudden death or endocarditis), leading to clinical overreaction, overtreatment, and unnecessary induction of disability. Though some physical complications may be prevented by recognizing severe MVP, there is substantial risk of iatrogenic harm by attributing complex symptoms and illness behavior to mild MVP, which is probably a normal variant. A three-dimensional analysis of illness experience is presented that may be of use in conceptualizing the clinical approach to overlap syndromes such as mild MVP. Conservative criteria for the diagnosis of significant MVP have been developed at the National Institutes of Health. Treatment of patients with mild MVP must emphasize that it is a normal variant without serious consequences. Because the risks of overmedicalization are so substantial, the impact of diagnostic labels on individual patients and society must be analyzed continually.