Arteriovenous Malformations (AVM)

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.


Where your AVM is, how big it is and if it is has ruptured all affect which treatment is right for you. If you have been diagnosed with an AVM or have symptoms of an AVM that has not ruptured, find a neurology expert to help you now. Skilled surgeons use advanced tools to remove AVMs. Treatments include:.

Neurology Medical Management

Brain Aneurysm Clipping

Main Line Health offers brain aneurysm clipping to help prevent an aneurysm from life-threatening rupture.

Endovascular Coiling for Treating Hemorrhagic Stroke

If left untreated, hemorrhagic stroke can result in serious neurological deficits or death. Endovascular Coiling is one of the procedures offering new hope to hemorrhagic stroke patients who had been told previously that they had no further treatment options.


Stroke and Neurointervention

Main Line Health is one of few community health systems offering state-of-the-art neurointervention care. Through our collaboration with the Jefferson Hospital for Neuroscience, our Neurointervention Program is an accredited thrombectomy-capable stoke center.


Discover how Main Line Health neurosurgeons provide expert care, from routine to complex spinal and nervous system conditions for patients.


The neurology team at Main Line Health treats and manages conditions such as migraines, multiple sclerosis, Parkinson’s disease and more.