Your circulatory system consists of the heart and blood vessels. Arteriovenous malformations (AVMs) are defects in the blood vessels—the veins, capillaries, and arteries—of the circulatory system. A malformation is an abnormal connection between the veins and arteries that interferes with the body’s ability to circulate blood. It is usually congenital, meaning that this condition is typically present at birth. Although malformations can begin anywhere in your body, some develop in the brain and spinal cord region, causing seizures and headaches.

What Causes AVMs?

The cause of AVMs is unknown. Some doctors believe they occur in the womb or shortly after birth, and appear later as the child ages.

Children born with an AVM condition may have a bluish tint to their skin due to the absence of oxygenated blood circulating through the body. The skin tends to darken to a deep red or purple as children age and the condition worsens.

Who Is at Risk for Arteriovenous Malformations?

If you have family members who have AVMS, you are at greater risk. A history of unexplained bleeding may also place you at risk for AVMs.

What are the Symptoms of AVM?

The symptoms of AVM vary depending on:

  • location of the AVM
  • size of the AVM
  • risk factor for the AVM
  • type of blood vessel involved in the AVM

You may not have significant symptoms if you have an AVM in the brain. In some cases, brain AVMs may cause headaches or seizures; however, due to lack of symptoms, this type of AVM often goes undiagnosed or unnoticed until it presents life-threatening symptoms.

Common symptoms for AVMs found in the brain include:

  • bleeding in the skull
  • seizure
  • headache
  • confusion
  • memory lapses
  • hallucinations
  • dementia

If the AVM is elsewhere in the body, the symptoms may be more pronounced.

Common symptoms for AVMs found in the limbs and spinal cord include:

  • muscle weakness
  • inability to move a limb
  • lack of coordination

Common symptoms for AVMs found in the organs, chest, or abdomen include:

  • abdominal pain
  • back pain
  • chest pain
  • irregular sounds in the affected blood vessels

Common symptoms in children under 2 years of age:

  • congestive heart failure (the heart is not able to pump out the blood that pumps into it)
  • seizures
  • hydrocephalus, an increase in fluid in the brain that causes swelling

How Are AVMs Diagnosed?

Your doctor will perform a physical examination and several tests to confirm diagnosis. It is important to rule out other health problems that can mimic the symptoms of AVMs.

Imaging tools and methods used to diagnose AVMs include:

  • CT scan, an imaging tool used to produce detailed images of the inside of the body
  • Angiography, which determines how well the blood circulates in the body
  • MRA (magnetic resonance angiogram), a device that takes and produces images of the blood vessels

How Are AVMs Treated?

A doctor will implement a treatment plan based on the patient’s age, condition, and physical health. The most important goal is to prevent internal bleeding, which can lead stroke or death.


Though medication may be prescribed, it does not cure AVMs. Medications are used to control pain and seizures.


Surgery to repair or remove damaged blood vessels is an option.

Conventional surgery of the brain or spinal cord is successful in treating AVMs. But arteriovenous malformations found deep in the brain or spinal cord tissue may require a procedure called endovascular embolization. A thin, flexible tube called a catheter is guided to the AVM to close up the abnormal connection. It doesn’t repair the AVM, but does reduce blood flow to it and makes surgery safer.

A procedure called radiosurgery may also be performed. This involves using a highly concentrated beam of radition and focusing it directly on the site of the AVM. The radiation damages the walls of the blood vessels leading to the AVM, but does not always destroy the AVM itself.

What Is to Be Expected in the Long Term?

AVMs cannot be prevented. But the symptoms can be treated and managed with proper medical care. Taking prescribed medications can help you avoid bleeding problems, pain, and other complications. Managing high blood pressure, avoiding medications that thin the blood, and keeping regular appointments with a neurologist can help monitor your condition and prevent complications.

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