The epidemiology and Etiology of Hemorrhoids

Abstract

There have been few articles regarding the epidemiology of hemorrhoids, therefore the prevalence of hemorrhoids is not well documented. In the USA, an annual nationwide health questionnaire showed a prevalence rate of 4.4%. In both sexes, a peak in prevalence was noted from age 45-65 years. There seems to be a fall in the rate of hospital visits in both the USA and the UK. The etiology and pathophysiology is uncertain as well. Between the 18^th and 19^th Centuries, several hypotheses were postulated. Examples include the abnormal venous dilatation theory and erectile tissue metaplasia theory. In the late 20^th Century, several studies argued that little evidence was found supporting abnormal venous dilatation, and that hemorrhoidal symptoms may arise from distal displacement of the anal vascular cushion. Since then, the sliding anal lining theory has been thought of as the main etiology of hemorrhoids. Despite the fact that the pathogenesis of hemorrhoids still remains elusive because of the diversity and complexity of their pathophysiology, it is reasonable to assume that both vascular tissue factors and the connective tissue factors contribute to the etiology of hemorrhoids.