What is "arteriovenous malformation"

n. (context pathology English) A congenital disorder in which artery are connected directly to veins rather than through capillaries that distribute oxygen and nutrients. These connections, often called a nidus, can be extremely fragile and prone to bleeding.

Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system, but can appear in any location. Although many AVMs are asymptomatic, they can cause intense pain or bleeding or lead to other serious medical problems.

AVMs are usually congenital and belong to the RASopathies. The genetic transmission patterns of AVM, if any, are unknown. AVM is not generally thought to be an inherited disorder, unless in the context of a specific hereditary syndrome.