What Is an Aneurysm?

Video Topic : Learn how aneurysms form and ways they are treated and prevented.

What Is an Aneurysm?

An aneurysm (AN-u-rism) is a balloon-like bulge in an artery. Arteries are blood vessels that carry oxygen-rich blood to your body.

Arteries have thick walls to withstand normal blood pressure. However, certain medical problems, genetic conditions, and trauma can damage or injure artery walls. The force of blood pushing against the weakened or injured walls can cause an aneurysm.

An aneurysm can grow large and rupture (burst) or dissect. A rupture causes dangerous bleeding inside the body. A dissection is a split in one or more layers of the artery wall. The split causes bleeding into and along the layers of the artery wall.

Both rupture and dissection often are fatal.


Most aneurysms occur in the aorta, the main artery that carries oxygen-rich blood from the heart to the body. The aorta goes through the chest and abdomen.

An aneurysm that occurs in the chest portion of the aorta is called a thoracic (tho-RAS-ik) aortic aneurysm. An aneurysm that occurs in the abdominal portion of the aorta is called an abdominal aortic aneurysm.

Aneurysms also can occur in other arteries, but these types of aneurysm are less common. This article focuses on aortic aneurysms.

About 13,000 Americans die each year from aortic aneurysms. Most of the deaths result from rupture or dissection.

Early diagnosis and treatment can help prevent rupture and dissection. However, aneurysms can develop and grow large before causing any symptoms. Thus, people who are at high risk for aneurysms can benefit from early, routine screening.


Doctors often can successfully treat aortic aneurysms with medicines or surgery if they’re found in time. Medicines may be given to lower blood pressure, relax blood vessels, and reduce the risk of rupture.

Large aortic aneurysms often can be repaired with surgery. During surgery, the weak or damaged portion of the aorta is replaced or reinforced.

NIH: National Heart, Lung, and Blood Institute


An aneurysm is a bulge or "ballooning" in the wall of an artery. Arteries are blood vessels that carry oxygen-rich blood from the heart to other parts of the body. If an aneurysm grows large, it can burst and cause dangerous bleeding or even death.

Most aneurysms occur in the aorta, the main artery that runs from the heart through the chest and abdomen. Aneurysms also can happen in arteries in the brain, heart and other parts of the body. If an aneurysm in the brainbursts, it causes a stroke.

Aneurysms can develop and become large before causing any symptoms. Often doctors can stop aneurysms from bursting if they find and treat them early. They use imaging tests to find aneurysms. Often aneurysms are found by chance during tests done for other reasons. Medicines and surgery are the two main treatments for aneurysms.

NIH: National Heart, Lung, and Blood Institute

Dr. Watson: Aneurysms are an out-pouching of a vessel.

Dr. Oz: Sort of like a balloon`s being blown up past its comfort space, it gets bigger and bigger and bigger and eventually (POP), it pops.

VO: Many aneurysms never rupture, and often people are not even aware they have one.

VO: Most aneurysms - 3 out of 4 - are found by chance when a diagnostic test, like an X-ray or an ultrasound, is performed for a different reason.

VO: Aneurysms can happen anywhere in the body. The most common and most dangerous occur in the brain - where a cerebral aneurysm can lead to stroke...in the carotid artery in your neck...or in the aorta.

VO: The aorta is the largest blood vessel in your body. It`s as wide as a garden hose, comes directly out of your heart and runs the length of your torso, feeding blood to many other vessels.

Dr. Oz: The aortic aneurysm is an often under-diagnosed problem because you don`t really have any symptoms until it bursts and as you might guess, when the major tube carrying blood from the heart bursts, the blood goes all over the place, but it doesn`t go where it needs to go which is to your brain and the rest of your body and those folks die in an alarmingly high rate.

VO: Aneurysms are caused by constant pressure on the lining of the blood vessels, due to factors such as hypertension, atherosclerosis, genetics, smoking, aging, and sometimes injury, infection or inflammation.

VO: The walls of your blood vessels have 3 layers. The middle elastic section is the largest, and when under constant pressure, it can thin out considerably to form an aneurysm.

Dr. Watson: So basically it`s just like if you keep pounding against anything for any given amount of time, you`re going to get a weakness in that area. When you get enough weakness in a vessel in a certain area, an aneurysm forms.

VO: Often doctors will take a `watch and wait` approach to an aneurysm, but surgery may be necessary to treat an aneurysm that has gotten too big, or is growing too rapidly.

VO: For cerebral aneurysms, a surgical clip is often used.

VO: For abdominal aortic aneurysms. There are two main surgical procedures.
The more traditional surgery uses a graft to replace a section of the aorta...and a newer approach involves feeding a stent up into the aorta to essentially brace the walls of the vessel.

VO: But as in all cardiovascular disease, doctors recommend a preventative approach. Quitting smoking, controlling your blood pressure and cholesterol and maintaining healthy physical activity are the best ways to avoid an aneurysm.

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