Vaginal infections in adult women. Often trivialized by the medical profession, vaginitis in adult women is not only extremely common but is the source of considerable distress and often results in marked suffering. Epidemiologic studies described in this article indicate the high prevalence of vaginitis and the large number of causes. Although the majority of infections in women are due to bacterial vaginosis, VVC, and trichomoniasis, it is clear that many other causes exist, and we have yet to discover the etiology of many clinical syndromes. Considerable progress has been made in understanding the pathogenesis of the three common vaginitides. Although excellent progress has been made by the pharmaceutical industry in providing new drugs for vaginitis, any further progress will require a better understanding of etiology and pathogenesis. Vaginitis causes major symptoms and is more than a nuisance problem. Clinicians owe it to their patients to attempt to make an accurate diagnosis and not to rely on empiric therapy. 