Aortic Aneurysm

Also known as abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA)
An aneurysm is a balloon-like bulge in an artery. Arteries are blood vessels that carry blood from your heart to your organs. Aortic aneurysms are aneurysms that occur in the aorta, the main artery carrying oxygen-rich blood to your body. This health topic focuses on two types of aneurysms that affect the aorta: abdominal and thoracic aortic aneurysms.

The aorta has thick walls that withstand normal blood pressure. However, certain medical problems, genetic conditions, and trauma can damage or weaken these walls. The force of blood pushing against the weakened or injured walls can cause an aneurysm.

An aortic aneurysm can grow large and either rupture or split. A split is called a dissection and, like a rupture, is life-threatening. Early diagnosis and treatment may prevent serious or life-threatening complications. However, aortic aneurysms can develop and grow large before causing any symptoms. Doctors may be able to slow the growth of an aortic aneurysm with medicines or repair it with surgery if it is found before it ruptures or dissects.

Explore this Health Topic to learn more about aortic aneurysms, our role in research and clinical trials to improve health, and where to find more information.

Types - Aortic Aneurysm

There are two types of aortic aneurysm: thoracic aortic aneurysm and abdominal aortic aneurysm. Until recently, it was thought that thoracic aortic aneurysms and abdominal aortic aneurysms were due to the same cause. Now we know that the two types are separate diseases with different risk factors and causes.

Abdominal aortic aneurysm
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The most common place for an aneurysm is the part of the aorta that runs through the abdomen, called the abdominal aorta. The abdominal aorta provides oxygen-rich blood to the tissues and organs of the abdomen and lower limbs.

Thoracic aortic aneurysm
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A thoracic aortic aneurysm is a less common aneurysm that occurs in the chest portion of the aorta, above the diaphragm.

Aortic aneurysms.
Aortic aneurysms. Figure A shows the thoracic and abdominal sections of a normal aorta. Figure B shows a thoracic aortic aneurysm. The one in this figure is located behind the heart. Figure C shows an abdominal aortic aneurysm.

Why are aneurysms more common in the abdominal aorta than in the thoracic aorta?

Causes - Aortic Aneurysm

Aortic aneurysms are caused by a weakening of the aortic wall due to damage or injury. Many health conditions and lifestyle habits can put you at risk for damage to the aortic wall, including high blood pressure and smoking. A bulge may occur where the wall has been damaged and is weakened. If left untreated, the aortic wall will continue to weaken, and the bulge will grow. If it becomes large enough, the aortic aneurysm may rupture.

Look for
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  • Treatment will discuss medicines, heart-healthy lifestyle changes, and procedures that your doctors may recommend if you are diagnosed with an aortic aneurysm.

Risk Factors - Aortic Aneurysm

You may have an increased risk of developing an aortic aneurysm because of your age, family history, genes, lifestyle habits, medical conditions, or sex.

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Your risk for aortic aneurysms goes up as you age. Abdominal aortic aneurysms are most common in adults after age 65.

Family history and genetics
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Several familial or genetic conditions increase your risk for a thoracic aortic aneurysm. These include:

Abdominal aortic aneurysms also run in families. One in 10 people with abdominal aortic aneurysms have a family history of abdominal aortic aneurysms. The chance of developing an abdominal aortic aneurysm is 1 in 5 for people who have a first degree relative with the condition, which means a parent, brother, sister, or child was affected.

Lifestyle habits
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Some lifestyle habits increase your risk of having an aortic aneurysm. These include:

  • Cigarette smoking, which increases your risk for an aortic aneurysm, especially an abdominal aortic aneurysm. If you are a current smoker, an abdominal aortic aneurysm may grow more quickly and be more likely to rupture.
  • Using stimulants such as cocaine
  • Weight lifting

Medical conditions
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Medical conditions that are risk factors for aortic aneurysms include:

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Men are more likely than women to develop aortic aneurysms. However, an existing aneurysm is more likely to rupture at a smaller size in women than in men.

Screening and Prevention - Aortic Aneurysm

If you have known risk factors for developing an aortic aneurysm, your doctor may recommend screening. To screen for an aortic aneurysm, your doctor may recommend an imaging study to look at and measure the aorta. An aneurysm can develop and grow without any symptoms until it ruptures or dissects—events that are both life-threatening. If the aneurysm is found early, treatment or surgery may slow its growth and prevent rupture or dissection.

Screening tests
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Screening tests for aortic aneurysms will show whether the diameter of your aorta is larger than normal. If it is larger than normal, your doctor may recommend a later, second screening to check for growth.

  • Computed tomography (CT), magnetic resonance imaging (MRI), or echocardiography may be used for thoracic aortic aneurysm screening. The choice will depend on your age and other medical conditions. The normal diameter of the thoracic aorta depends on where it is measured and whether you are male or female.
  • Ultrasound may be used to screen for an abdominal aortic aneurysm and to monitor the aorta over time.

Who should be screened?
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Certain groups of people may be screened for a thoracic aortic aneurysm. They include:

  • People who have Marfan, Loeys–Dietz, Ehlers–Danlos, or Turner syndrome
  • First-degree relatives of people who have a thoracic aortic aneurysm or a bicuspid aortic valve (BAV)–associated thoracic aortic aneurysm
  • Relatives of people with familial thoracic aortic aneurysms who also have the genetic mutations

Certain groups of people who may be screened for abdominal aortic aneurysm include:

  • Men and women 65 to 75 years old who have ever smoked or who have a first-degree relative who had an abdominal aortic aneurysm
  • Men 65 to 75 years old who never smoked but have other risk factors, such as a family history of abdominal aortic aneurysms in any family member, other vascular aneurysms, or coronary heart disease
  • Men and women more than 75 years old who are in good health, who have ever smoked, or who have a first-degree relative who had an abdominal aortic aneurysm.
  • People who have peripheral artery disease, regardless of age, sex, smoking history, or family history

Prevention strategies
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If you have risk factors for developing an aneurysm, your doctor may recommend heart-healthy lifestyle changes to help prevent the condition, including:

Look for
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  • Diagnosis will discuss tests and procedures that your doctor may use to diagnose an aortic aneurysm.
  • Living With will discuss what your doctor may recommend to prevent your aortic aneurysm from becoming larger or causing complications.
  • Research for Your Health will discuss how we are using current research and advancing research to prevent aortic aneurysm.

Signs, Symptoms, and Complications - Aortic Aneurysm

An aortic aneurysm may not cause any signs or symptoms until the aneurysm ruptures or dissects. The types of symptoms that occur before a rupture will depend on the location of the aneurysm and whether it has become large enough to affect other parts of your body. An aneurysm that ruptures or dissects is life-threatening.

Signs and symptoms
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If you do have signs and symptoms of an aortic aneurysm, they may include:

  • Difficult or painful swallowing if the aneurysm is pushing on your esophagus
  • Difficulty breathing if it is pushing on your trachea, or windpipe
  • Feeling full after not eating very much
  • Hoarseness
  • Pain in the neck, jaw, back, chest, abdomen or shoulder, depending on where the aneurysm is located
  • Pulsating or throbbing feeling in your abdomen
  • Shortness of breath if the aneurysm is pressing on your lung
  • Swelling of the face, neck, or arms if the aneurysm is pushing on the superior vena cava. The superior vena cava is the main vein that returns blood from your upper body to your heart.

If you know you have an aortic aneurysm, it is important to know the signs and symptoms of a rupture, since quick treatment may be life-saving. Signs and symptoms of a rupture may include:

  • Light-headedness
  • Rapid heart rate
  • Sudden, severe pain in your abdomen, chest, or back

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Complications from aortic aneurysms may be life-threatening and may include:

  • Aortic dissection, which is a tear in the inner layer of the aortic wall. It causes blood to collect between the inner and middle layers of the aortic wall. This may lead to rupture of the aorta or not enough blood flow to your organs.
  • Aortic insufficiency and aortic regurgitation, both of which occur when the aortic valve does not close properly because a nearby section of the aorta is enlarged. This allows some backward flow of blood back into the heart. As a result, your heart must work harder, which may lead to heart failure.
  • Aortic rupture, which causes dangerous bleeding inside the body and can lead to shock
  • Cardiac tamponade
  • Kidney failure from lack of blood flow to the kidneys
  • Lack of blood flow to the bowels, which causes inflammation and injury in the large intestine

Look for
- Aortic Aneurysm

  • Diagnosis will discuss tests and procedures used to detect aortic aneurysms and help rule out other conditions that may mimic aortic aneurysm.
  • Treatment will discuss treatments and their complications or side effects.

Diagnosis - Aortic Aneurysm

To diagnose an aortic aneurysm, your doctor will do a physical exam and an imaging test to confirm a screening test. An abdominal aortic aneurysm is diagnosed when your abdominal aorta is three centimeters or greater in diameter. The normal diameter of the thoracic aorta depends on your age, your sex, and which part of the thoracic aorta is measured.

Physical exam
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During a physical exam, your doctor may do the following to look for an aortic aneurysm:

  • Feel your abdomen to see whether an abdominal aortic aneurysm can be felt
  • Listen to your heart for a heart murmur, softer heart sounds, or other changes in your blood flow that could be a sign of an aneurysm
  • Check your pulse in your arms and legs to see whether it feels weaker than normal
  • Look for signs and symptoms of medical conditions that are risk factors for an aortic aneurysm, such as Marfan or Ehlers-Danlos syndromes. This may include looking at your skin, muscles and bones, eyes, head and face, and heart.

Diagnostic tests and procedures
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Different types of imaging studies may be used to diagnose your aortic aneurysm. Consider discussing the options with your doctor. Your doctor may order some of the following imaging tests to confirm or diagnose an aortic aneurysm:

  • Computed tomography (CT) to provide information about the location, size and shape of an aneurysm. This may be the first test you get if you have sudden back or abdominal pain, if you already know you have an aortic aneurysm, or if your doctor feels a pulsating bulge in your abdomen while examining you. CT can provide information about the entire aorta, but for routine screening other diagnostic tests like echocardiography or ultrasound may be done first.
  • Echocardiography to provide information about the size of the aortic aneurysm and about the thoracic aorta, which is close to heart. Other parts of the thoracic aorta are better seen with other imaging studies such as CT or magnetic resonance imaging (MRI).
  • MRI to provide information about the size, shape, and location of the aneurysm
  • Ultrasound to provide information about the size of the abdominal aortic aneurysm. If you have abdominal or back pain, an ultrasound can check for an abdominal aortic aneurysm or other possible causes of your pain. Once an aortic aneurysm is seen or suspected on ultrasound, you may have a CT scan or an MRI to provide more details about the shape or location of the aneurysm.

Tests for other medical conditions
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Some conditions may mimic the symptoms of abdominal aortic aneurysms. To help diagnose an aortic aneurysm, your doctor may need to perform CT or ultrasound tests to find out whether your symptoms may be caused by other medical conditions, including:

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Treatment - Aortic Aneurysm

Treatment for your aortic aneurysm will depend on its cause, its size and location, and the factors that put you at risk. Small aortic aneurysms may be managed with healthy lifestyle changes or medicine. The goal is to slow the growth of the aneurysm and lower the chance of rupture or dissection. Your doctor may treat other medical conditions that raise your risk for rupture or dissection, such as high blood pressure, coronary heart disease, chronic kidney disease, and high blood cholesterol. Surgery may be recommended to repair large aneurysms.

Healthy lifestyle changes
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Your doctor may recommend heart-healthy lifestyle changes, such as the following:

  • Quitting smoking to slow the growth of the aneurysm
  • Heart-healthy eating to help lower high blood pressure or high blood cholesterol
  • Managing stress to help control high blood pressure, especially for thoracic aortic aneurysms. Your doctor may also suggest that you avoid heavy weightlifting and powerful stimulants, such as cocaine.

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Your doctor may recommend medicines to treat an aortic aneurysm, including:

  • Aspirin, especially if you have other cardiovascular risks
  • Blood pressure medicines to lower blood pressure, slow down aneurysm growth, and lower the risk of rupture. These medicines include beta blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs).
  • Statins to control cholesterol levels, and stop or slow the growth of aortic aneurysms

Procedures or surgery
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Depending on the cause or size of an aortic aneurysm or how quickly it is growing, your doctor may recommend surgery to repair it. Rupture or dissection of an aneurysm may require immediate surgical repair.

  • Open surgical repair is the most common type of surgery. You will be asleep during the procedure. Your surgical team first makes a large incision, or cut, in your abdomen or chest, depending on the location of the aneurysm, then removes the aneurysm and sews a graft in its place. This graft is typically a tube made of leak-proof polyester. Recovery time for open surgical repair is about a month.
  • Endovascular aneurysm repair (EVAR) is less invasive than open surgical repair. This is because the surgical cut is smaller, and you usually need less recovery time. EVAR is used to repair abdominal aortic aneurysms more often than to repair thoracic aortic aneurysms. During the procedure, your surgical team makes a small cut, usually in the groin, then guides a stent graft—a tube covered with fabric—through your blood vessels up to the aorta. The stent graft then expands and attaches to the aortic walls. A seal forms between the stent graft and the vessel wall to prevent blood from entering the aortic aneurysm.
Endovascular repair. The illustration shows the placement of a stent graft in an abdominal aortic aneurysm.
Endovascular repair. The illustration shows the placement of a stent graft in an abdominal aortic aneurysm. In figure A, a catheter is inserted into an artery in the groin. The catheter is threaded to the abdominal aorta, and the stent graft is released from the catheter. In figure B, the stent graft is expanded and allows blood to flow through the aorta.


Complications of both types of aortic aneurysm repair can occur, and they may be life-threatening. These include:

  • Bleeding and blood loss
  • Blood clots in blood vessels leading to the bowel, kidneys, legs, or in the graft
  • Damage to blood vessels or walls of the aorta when placing the stent graft. The stent graft may also move after it is placed.
  • Endoleak, which is a blood leak around the stent graft into the aneurysm. Endoleak may cause rupture of the aneurysm if not treated.
  • Gastrointestinal bleeding, which rarely occurs if an abnormal connection forms between the aorta and your intestines after the repair. Blood may show up in your stool, or your stool may be black.
  • Heart complications such as heart attack or arrhythmia
  • Decreased blood flow to the bowels, legs, kidneys or other organs during surgery. This may lead to injury to these organs.
  • Infection of the incision or the graft
  • Kidney damage
  • Spinal cord injury which may cause paralysis
  • Stroke

Look for
- Aortic Aneurysm

  • Research for Your Health will discuss how we are using current research and advancing research to treat people with aortic aneurysms.
  • Living With will discuss what your doctor may recommend, including lifelong lifestyle changes and medical care to prevent your condition from recurring, getting worse, or causing complications.

Living With - Aortic Aneurysm

If you have an aortic aneurysm, it is important to follow your treatment plan and get ongoing medical care. Your doctor may recommend steps to prevent complications such as rupture or dissection.

Monitor your condition
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As aneurysms increase in size, they expand more quickly and are more likely to rupture. Your doctor may recommend regular imaging tests, such as CT scans, MRIs, or ultrasounds, to see how quickly your aortic aneurysm is growing and whether you need surgery. How often this imaging is done depends on your risk factors and the cause and size of your aortic aneurysm. Those who have had surgery to repair an aortic aneurysm may need regular monitoring. In this case, the imaging studies will check for leaks and make sure the stent graft has not moved from its original location.

If you have a genetic condition that may cause aortic aneurysms, your doctor may recommend monitoring.

Return to Treatment to review possible treatment options for aortic aneurysms.

Prevent complications over your lifetime
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To help you prevent complications due to an aortic aneurysm, your doctor may recommend the following:

  • Continue any medicines as prescribed by your doctor, including those to control other medical conditions such as high blood cholesterol and high blood pressure.
  • Take antibiotics, if they are prescribed, to prevent infection of the graft before dental and other medical procedures.
  • If you had a thoracic aortic aneurysm, avoid heavy lifting, stress, and other situations that might raise your blood pressure.
  • Quit smoking and adopt a heart-healthy lifestyle.
  • Follow all medical instructions given by your doctor. Recovery after open surgical repair may take months.
  • If needed, allow your doctor to screen you for aneurysms in other locations, such as your pelvis or legs.

Learn the warning signs of serious complications and have a plan
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Learn the signs and symptoms of an aortic aneurysm and possible rupture or dissection. Contact your doctor immediately or call 9-1-1 if you experience any symptoms that may be related to your aortic aneurysm.

If you have had surgery to repair an aortic aneurysm, look for signs of possible graft infection, such as pain, drainage, or fever. Contact your doctor immediately with any concerns.

Research for Your Health

The NHLBI is part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH)—the Nation’s biomedical research agency that makes important scientific discovery to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders, including aortic aneurysms. Learn about the current and future NHLBI efforts to improve health through research and scientific discovery.

Improving health with current research
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Learn about the following ways the NHLBI continues to translate current research into improved health for people with aortic aneurysms. Research on this topic is part of the NHLBI’s broader commitment to advancing heart and vascular disease scientific discovery.

  • The NHLBI is advancing diagnosis and treatment of thoracic aortic aneurysms that have genetic causes. The National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Associated Cardiovascular Conditions (GenTAC) was established to help research and improve diagnosis and management of thoracic aortic aneurysms that have genetic causes. This comprehensive approach to thoracic aortic aneurysms from genetic mutations is helping to advance clinical management and treatment.
  • The NHLBI is providing guidance on future research in the area of thoracic aortic disease. The NHLBI Working Group on Research in Marfan Syndrome and Related Disorders included a summary of recommendations for future research in the area of thoracic aortic disease. These recommendations were included in and endorsed by the ACC/AHA 2010 Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease.
  • The NHLBI supports development of practice guidelines for abdominal aortic aneurysms. The NHLBI continues to support researchers whose work has been the basis for clinical guidelines used to treat patients with abdominal aortic aneurysms, such as the Society for Vascular Surgery practice guidelines on the care of patients with abdominal aortic aneurysms.
  • The NHLBI supports development of treatment guidelines by the American College of Cardiology and American Heart Association. The NHLBI supports experts who review the latest science and draft clinical guidelines, such as the 2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease, that health professionals consult when treating adults who have vascular diseases such as abdominal aortic aneurysms.

Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.

Advancing research for improved health
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In support of our mission, we are committed to advancing aortic aneurysm research in part through the following ways.

Learn about exciting research areas the NHLBI is exploring about aortic aneurysms.

Participate in NHLBI Clinical Trials

We lead or sponsor many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.

More Information

After reading our Aortic Aneurysm Health Topic, you may be interested in additional information found in the following resources.

Non-NHLBI resources
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