Arteriovenous malformations (AVMs) are groups of blood vessels in
your body that form in the wrong way. In AVMs, arteries and veins are abnormally
AVMs can form anywhere in the body. They often occur as the body
develops before birth or shortly after. Those that form in the brain or close to the
spinal cord are called neurological AVMs. These are most likely to have long-term
effects. They may reduce the amount of oxygen getting to the brain and spinal cord. AVMs
can also sometimes put pressure on nearby tissues.
Most people with an AVM don’t know they have one. They may not have
any symptoms or problems. Instead, AVMs are often found when healthcare providers treat
some other unrelated health concern. Or one of the blood vessels in an AVM may rupture,
revealing the problem. Sometimes AVMs are found only after death, during an autopsy.