Depends. It can be deadly serious or incidental - depending on the type and location. You should see a neurosurgeon to determine which one you have and what it needs for treatment.
Location. All depend of the location, the clinical manifestations, the type of avm.... But in general are not big deal...
Bleed risk. The overall risks of bleeding are 3-4% yearly. Each bleed episode carries a 25% risk of mortality. Overall risk of dying is therefore 1% yearly.
Often none. Unless it leaks, there would be no symptoms in most cases. Leaking can cause intense headache or stroke-like symptoms such as focal weakness, loss of speech or vision. Avm discovered after a minor stroke can be corrected before a major stroke. Family history of avm may prompt investigation in someone with no symptoms.
Congenital. An avm is a congenital malformation of brain and possibly spinal blood vessels. They predispose those that have them to neurologic symptoms and, potentially, bleeding. A thorough neurosurgical evaluation is essentially if an avm is suspected.
Localized deficits. A brain AVM is a connection of arteries directly to veins, without going through capilaries. When the flow increases it can produce a 'steal' effect by taking blood from surrounding tissue, resulting in an abnormality of brain fuction controled by the area of the 'steal'. another manifestation is a result of bleeding of the aVM.
Hemorrhage. Most of the damage of an arteriovenous malformation occurs when the blood vessel or vessels are spontaneously ruptured and bleed into the brain, causing pressure and damage to the brain. The same can occur with an av malformation in the brain stem or spine.
Multiple ways. The avm can compress nearby tissue and cause a stroke, or interfere with blood flow and also create tissue damage. If rupture occurs there can be a subarachnoid hemorrhage, with both local and more widespread problems. Brain avm's may cause seizures. Small avm's are unlikely to be an issue, but rarely, the ones in the spinal cord can cause paralysis.
More information. Arterio-venous malformations at the basic level is an abnormal connection to an artery and vein. They can occur anywhere in the body and can be something you are born with (congenital) or acquired, usually through penetrating trauma. They can cause problems with bleeding or shunting of blood or allowing bacteria or clots to pass through them. The symptoms relate to where they are located.
Brain. Av malformations usually form in the brain.
AVM. In various parts of the brain (superficial/deep and eloquent/noneloquent parts) or spinal cord.
Studies... Angiography can detect the majority of vascular lesions; although a good number of them are detected while undergoing numerous other procedures for other things (ct scans, ultrasounds, etc.).
CTA, MRAngio. The gold standard to diagnose a-v malformations and vascular anomalies is an angiogram. This may be a ctangio, mrangio or selective digital substraction angiography.
Answer is complex. Avm are communications which in variable degrees exist in different parts of the body. Most are congenital (you are born with) others can be related to injury or trauma. It also depends how large the avm are and if they cause symptoms besides the esthetic concern.
Vascular Abnormality. A pulmonary arteriovenous malformations (pavm) is a rare vascular abnormality of the lung. Most cases tend to be simple avm's (single feeding artery) although up to 20% of cases can have complex (2 or more) feeding vessels. They can be multiple in about 1/3 of cases.
Nidus of vessels. Abnormal communication between a pulmonary artery and vein with no normal capillary bed in between them.
Vascular neurosurg. Since the diagnosis is already established, you need to address treatment. Initial bleeding from an avm ranges from 4->20%.Without hemorrhage the risk of bleeding is1->4%/yr. A vascular neurosurgeon can steer you to the appropriate treatment, surgery, endovascular glue embolization, or direct beam radiation therapy or a combination of therapies. Find a known regional center.
Neurosurgeon. Of course it depends on where the avm is located... For those involving the brain and spinal cord a neurosurgical evaluation is usually recommended.
Neurosx. Assuming u mean brain, since can get avm anywhere. Treatment options are neurosurgeon for surgery, or interventional radiology for embolization. Common to have embolization prior to surgery. Upon finding an avm on a scan, you will be referred to a specialist.