What are the health consequences of arteriovenous malformations?

Size matters: Avms can bleed or cause strokes, either of which can cause a huge range of problems depending on location and size. Some avms are so large that they press on nearby brain tissue like a tumor would. Much of the health consequences depend in the size of the avms.

Location: Avms may be located in the brain (as 1st answer noted) or in the "gut" (gastrointestinal tract). The location, size, and severity help determine the consequences.