What is an aneurysm?

An aneurysm is a bulging, weak area in the wall of a blood vessel. It may occur in any blood vessel but most often develops in an artery rather than a vein. An aneurysm can be categorized by its location, shape, and cause.

An aneurysm may be found in many areas of the body, such as:

Brain (cerebral aneurysm)
Aorta (aortic aneurysm)
Neck
Intestines
Kidney
Spleen
Blood vessels in the legs (iliac, femoral, or popliteal aneurysm)

The most common type of aneurysm is in the aorta. The aorta is the largest artery in the body. The aorta carries oxygenated blood from the heart to the body. A thoracic aortic aneurysm occurs in the chest cavity. An abdominal aortic aneurysm occurs in the abdomen.

What causes an aneurysm?

An aneurysm may be caused by factors that result in the breakdown of the artery wall. The exact cause isn't fully known. Atherosclerosis (hardening of the arteries) may be part of the cause.

Other causes of aneurysms are related to where they occur. Examples may include:

Type of aneurysm

Causes of aneurysms

Abdominal aortic aneurysm (AAA)

Atherosclerosis (especially in the part of the abdominal aorta below the kidneys, called an infrarenal aortic aneurysm)
Genetic disorders
Giant cell arteritis (a disease that causes inflammation of the temporal arteries and other arteries in the head and neck)
Infection

Cerebral aneurysm

Congenital (present at birth)
High blood pressure
Atherosclerosis
Head injury

Common iliac artery aneurysm

Atherosclerosis
Pregnancy
Infection
Injury after lumbar or hip surgery

Femoral and popliteal artery aneurysm

Atherosclerosis
Injury
Congenital disorders

Who is at risk for an aneurysm?

You are at higher risk for an aneurysm if you have atherosclerosis.

Risk factors you can’t control include:

Older age
Male
Family history
Genetic factors

Risk factors you can control include:

High cholesterol
High blood pressure
Smoking
Diabetes
Obesity

Men ages 65 to 75 who have ever smoked should have a one-time ultrasound screening for abdominal aortic aneurysm (AAA). If you are a male between 65 and 75 and have never smoked, your healthcare provider may advise screening based on other risk factors such as your health history or family history.

What are the symptoms of an aneurysm?

Aneurysms may have no symptoms. If there are symptoms, they will depend on the location of the aneurysm in the body. Pain is the most common symptom. This is true no matter where the aneurysm is.

Symptoms that may occur with different types of aneurysms may include:

Type of aneurysm

Symptoms

Abdominal aortic aneurysm (AAA)

Constant pain in abdomen, chest, lower back, or groin area

Cerebral aneurysm

Sudden severe headache, nausea, vomiting, visual disturbance, loss of consciousness

Common iliac aneurysm

Lower abdominal, back, or groin pain

Femoral and popliteal artery aneurysm

Pulsating of the artery in the groin (femoral) or on the back of the knee (popliteal), pain in the leg, sores on the feet or lower legs

The symptoms of an aneurysm may look like other medical conditions or problems. See your healthcare provider for more information.

How is an aneurysm diagnosed?

What tests you’ll need depends on the location of the aneurysm. Along with a complete medical history and physical exam, tests for an aneurysm may include:

CT scan. This imaging test uses X-rays and computer technology to make horizontal (axial) images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than standard X-rays.
MRI. An MRI uses large magnets, radio waves, and a computer to make detailed images of organs and structures in the body. It does not use X-rays.
Echocardiogram (echo). This procedure evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that makes a moving picture of the heart and heart valves.
Arteriogram (angiogram). This is an X-ray image of the blood vessels used to evaluate various conditions, such as aneurysm, stenosis (narrowing of the blood vessel), or blockages. A dye (contrast) will be injected through a thin flexible tube placed in an artery. This dye will make the blood vessels visible on the X-ray.
Ultrasound. An ultrasound uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. An ultrasound is used to view internal organs as they function. And it is used to assess blood flow through various vessels.

How is an aneurysm treated?

Treatment options for an aneurysm may include:

Monitoring. Your healthcare provider may monitor the size and rate of growth of your aneurysm with ultrasounds every 6 months to 12 months. This is part of a "watchful waiting" approach for smaller aneurysms.
Managing risk factors. Steps such as quitting smoking, controlling blood sugar if you have diabetes, losing weight if you are overweight, and controlling dietary fat intake may help to control the progression of the aneurysm.
Medicine. Medicine can help control factors such as high cholesterol and high blood pressure.
Surgical repair. Surgical repair of the aneurysm can be done with large incisions and grafts or with smaller incisions, X-ray images, and a stent-graft combination.

What are possible complications of an aneurysm?

The biggest complication of an aneurysm is that it may tear (dissect) or rupture.

Because an aneurysm may continue to increase in size, along with progressive weakening of the artery wall, treatment is required to prevent rupture of an aneurysm. The larger an aneurysm becomes, the greater the risk for rupture (bursting). Rupture can cause life-threatening bleeding and possibly death. Loss of blood flow to the area the artery provides circulation to can cause organ and tissue death, which may lead to amputation of the dead tissue.

Living with an aneurysm

Until your aneurysm reaches the point where it needs to be repaired, it’s very important to follow your healthcare provider’s advice closely.

Have ultrasound screenings done as often as advised
Follow advice about diet, exercise, and weight control
Take medicine as prescribed

When should I call my healthcare provider?

If your symptoms get worse or you have new symptoms, call your healthcare provider right away. Get immediate medical attention if you have a sudden, severe pain in the area of the aneurysm. This could be a sign that the aneurysm has ruptured.

Key points about aneurysms

An aneurysm is a bulging, weak area of an artery wall and can occur anywhere in the body.
The most common symptom is pain in the area of the aneurysm.
An aneurysm is repaired once it reaches a certain size. This is to prevent rupture of the blood vessel.
Treatment of an aneurysm includes controlling risk factors. These include blood pressure, cholesterol, diabetes, and stopping smoking. These things may require changes in lifestyle and medicine.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your healthcare provider tells you.
At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your healthcare provider gives you.
Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you do not take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your healthcare provider if you have questions.