A localized dilation of the wall of a blood vessels, usually caused by atherosclerosis and hypertension, or less frequently, by trauma, infection, or a congenital weakness in the vessel wall.

Aneurysms are most prominent and significant in the aorta, but also occur in peripheral vessels and are fairly common in the lower extremities of older people, especially in the popliteal arteries.

A sign of an arterial aneurysm is a pulsating swelling that produces a blowing murmur on auscultation (the act...