An AVM is a tangle of blood vessels. It can cause pressure to build up in the blood vessel and prevent normal blood flow. If the pressure becomes too great or the wall of the AVM vessel weakens, a blood vessel can burst and blood can leak or spurt into the brain. This can damage parts of the brain that control vital body functions, such as sight, sensation, language, critical thinking, and movements. In some cases, problems caused by an AVM can even lead to death. The high blood flow in an AVM can also shunt the oxygen from the arteries directly to the veins, bypassing the brain capillaries. This shunting can lead to strokes. AVM can be treated based on the type, symptoms, and cause.