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.
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.
A thoracic aortic aneurysm is a less common aneurysm that occurs in the chest portion of the aorta, above the diaphragm.
Why are aneurysms more common in the abdominal aorta than in the thoracic aorta?
Abdominal aortic aneurysms may be more common than thoracic aortic aneurysms because of the differences in the walls of the aorta in these two areas. The middle layer of the aortic wall contains muscle cells. This muscular layer of the wall is thicker in the thoracic aorta, which makes it stronger. Also, blood flows to this layer, which may contribute to its strength.
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.
Your risk for aortic aneurysms goes up as you age. Abdominal aortic aneurysms are most common in adults after age 65.
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.
Some lifestyle habits increase your risk of having an aortic aneurysm. These include:
Medical conditions that are risk factors for aortic aneurysms include:
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.
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 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.
Certain groups of people may be screened for a thoracic aortic aneurysm. They include:
Certain groups of people who may be screened for abdominal aortic aneurysm include:
If you have risk factors for developing an aneurysm, your doctor may recommend heart-healthy lifestyle changes to help prevent the condition, including:
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.
If you do have signs and symptoms of an aortic aneurysm, they may include:
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:
Complications from aortic aneurysms may be life-threatening and may include:
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.
During a physical exam, your doctor may do the following to look for an aortic aneurysm:
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:
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:
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.
Your doctor may recommend heart-healthy lifestyle changes, such as the following:
Your doctor may recommend medicines to treat an aortic aneurysm, including:
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.
Complications of both types of aortic aneurysm repair can occur, and they may be life-threatening. These include:
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.
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.
To help you prevent complications due to an aortic aneurysm, your doctor may recommend the following:
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.
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.
Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.
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.
We lead or sponsor many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.
After reading our Aortic Aneurysm Health Topic, you may be interested in additional information found in the following resources.