What Is an Aneurysm?
An aneurysm is a permanent ballooning in the wall of an artery. The pressure of blood passing through can force part of a weakened artery to bulge outward, forming a thin-skinned blister.
Although any weak blood vessel can be affected, aneurysms usually form in the abdominal or thoracic portions of the aorta, the main blood vessel that carries blood from the heart, or in arteries nourishing the brain. Aneurysms in any of these places are serious, while those in more peripheral locations such as the leg are often less hazardous.
The gravest threat an aneurysm poses is that it will burst and cause a stroke or life-threatening massive bleeding (hemorrhage). If an aneurysm ruptures, the patient must be treated within minutes in order to have a chance of survival.
Early diagnosis and treatment are critical. Because aneurysms often produce either no symptoms or mild symptoms, routine examinations are strongly encouraged so that a doctor can regularly test for warning signs of a more serious problem. Even if it doesn't rupture, a large aneurysm can impede circulation and contribute to the formation of blood clots.
There are many types of aneurysms. Here are a few:
What Causes It?
Any condition that causes arterial walls to weaken or deteriorate can result in an aneurysm. The most common culprits are atherosclerosis and high blood pressure. Penetrating wounds and infections can also lead to an aneurysm. Some types are the result of congenital, or inherited, weakness in artery walls.
Medically Reviewed by Cynthia Haines, MD,�July 2005.
SOURCES: American Heart Association