Prevalence and risk factors of chronic venous insufficiency.

Venous disease in the legs occurs very commonly in the general population in Western countries. Around one third of women have trunk varices. A lower prevalence has been observed in men but some recent surveys have suggested that the occurrence in men may be comparable to that in women. The prevalence increases with age but the incidence of new cases appears to be constant throughout adult life. Open venous ulcers occur in about 0.3% of the adult population and a history of open or healed ulceration occurs in around 1%. The etiology of chronic venous disease in the legs is unknown. A genetic predisposition may be present but evidence for this and for a mode of inheritance is lacking. There is some suggestion that prolonged standing may be a risk factor but studies are open to considerable bias. In women, obesity and previous pregnancy has been associated with the presence of varicose veins but the evidence is inconsistent. There have been few well-conducted studies examining diet and bowel habit as a risk factor. The risk of ulceration is related to the severity of varicosities and venous insufficiency, and is increased following deep vein thrombosis. Much further research is required to investigate the cause of this common condition in the general population.