What is arteriovenous malformations?
Arteriovenous malformations (AVMs) occur when arteries and veins become connected to unusual blood vessels. AVMs can occur in any part of your body, but most often happen in the brain and spine. Your arteries carry blood that is full of oxygen away from your heart so your cells can use the oxygen. Your veins then carry the blood without oxygen back to your heart. Usually veins and arteries are connected by tiny blood vessels called capillaries. When you have an AVM, your arteries and veins are connected by unusual and large blood vessels that are not capillaries. These tangles cause your blood flow to speed up, put stress on your blood vessels and keep very important oxygen particles from reaching cells. AVMs are life-threatening. They are also very rare—less than one percent of people have an AVM. Most people with AVMs were born with them, though no one knows why the strange blood vessels form. Men and people with a family history of AVMs are at a higher risk of having one.
Symptoms of AVM
You may never have symptoms of an AVM. In many cases, doctors spot AVMs on MRIs or CT scans of your brain or spine when looking for other health problems. Depending on the location of your AVM, you could also experience headaches, seizures or numbness on one side of your body. In almost half of all cases, AVMs are not discovered until they rupture, putting your life at risk.
AVMs put stress on the walls of your blood vessels. Over time, the walls may weaken and form a bulge (called an aneurysm) or even rupture (called a hemorrhage). Hemorrhages damage your brain and threaten your life. Hemorrhages cause sudden symptoms such as:
- Extremely severe headache
- Seizure
- Weakness or numbness in part of your body
- Trouble seeing, such as blurriness or loss of vision
- Difficulty speaking or understanding what other people are saying
- Falling over or having trouble standing
If you have these symptoms, call 911 or have someone bring you to an emergency room immediately.