By Richard N. Fogoros, MD 

Updated on September 06, 2021

 Medically reviewed by Richard N. Fogoros, MD

An aortic aneurysm is a localized dilation of the aorta, the main artery in the body. The chief reason it is considered a problem is that sometimes aneurysms can rupture, leading to catastrophic internal bleeding. However, other serious complications are also possible.

Most typically, aortic aneurysms develop quite gradually, over a period of several years, so never grow to the point that rupture becomes likely. Such aneurysms rarely produce any symptoms.

However, in other cases, an aneurysm may grow much more rapidly and become quite large, causing symptoms. These symptoms are a sign that rupture is becoming more likely. When an aortic aneurysm ruptures the risk of death is very high—even if emergency surgery can be performed. For this reason, people who have an aortic aneurysm need close medical monitoring so that surgery can be performed electively before rupture actually occurs.

It is very important to know whether an aortic aneurysm is causing symptoms. Doctors need to act quickly if any patient with risk factors for an aortic aneurysm also describes symptoms that may be caused by such an aneurysm. These people should be screened right away.

And people who have been diagnosed with a small or medium-sized aortic aneurysm, and are being monitored for it, need to be aware of what symptoms to look for and report any such symptoms to their doctor right away.

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Types of Symptoms

The symptoms caused by an aortic aneurysm depend, to some extent, on whether it is a thoracic aortic aneurysm or an abdominal aortic aneurysm.

The aorta is not only the largest blood vessel in the body, it is the longest one. It begins at the “top” of the heart so that when the heart ejects blood from the left ventricle and across the aortic valve into the aorta, the blood is flowing upward, toward the head. That first portion of the aorta is called the ascending aorta (since it directs the blood upward).

At the top of the chest, just beneath the throat, the aorta makes a U-turn—the so-called arch of the aorta—and it then tracks downward along the spine, through the chest and then the abdomen. This is called the descending aorta.

Along its whole length, the aorta gives off numerous blood vessels that supply the head, arms, thorax, and abdominal organs. Finally, in the lower abdomen the aorta divides into the two iliac arteries, which go on to supply the legs.

An aneurysm can develop at any point along the aorta’s course. If the aneurysm is located above the diaphragm (the breathing muscle at the base of the thorax) it is called a thoracic aortic aneurysm. If it is located below the diaphragm, it is called an abdominal aortic aneurysm. About 40 percent of aortic aneurysms are thoracic, and 60 percent abdominal.

Thoracic Aortic Aneurysm

An aneurysm of either the ascending aorta, the aortic arch, or the descending aorta above the diaphragm is called a thoracic aortic aneurysm. As with any aortic aneurysm, these usually start out quite small and grow gradually. If it becomes large enough a thoracic aortic aneurysm may cause several kinds of symptoms, depending on its location and on which other body structures it may begin to impinge upon.

These potential symptoms include:¹

• Chest pain. Chest pain caused by an aortic aneurysm is usually associated with an ascending aneurysm, or an aneurysm affecting the arch. This type of chest pain, in distinction to typical angina, is usually not directly related to exertion.

• Back pain. Back pain caused by a thoracic aortic aneurysm is often felt between the shoulder blades, or a bit lower. It usually occurs with an aneurysm of the descending thoracic aorta.

• Hoarseness. Dilation of the ascending aorta or the aortic arch can affect the recurrent laryngeal nerve, which supplies the vocal cords. There resulting vocal cord paralysis can lead to hoarseness.

• Cough. An aneurysm of the ascending aorta or the arch can impinge on the airways, producing cough.

• Dyspnea (shortness of breath). For similar reasons, an aneurysm of the ascending aorta or arch can cause dyspnea.

 Factors Influencing Aortic Aneurysm Outcomes

Abdominal Aortic Aneurysm

An abdominal aortic aneurysm is less likely to cause symptoms than a thoracic aortic aneurysm because there is generally more “room” in the abdomen for the aneurysm to grow before it affects other body structures. When symptoms do occur, it usually indicates that the aneurysm is large and/or is growing rapidly. These symptoms include:²

• Back pain. Back pain from an abdominal aortic aneurysm is felt in the lower part of the back, below the diaphragm.

• Deep abdominal discomfort. An abdominal aortic aneurysm can produce a deep, unrelenting discomfort, pain, or “fullness” in the abdomen.

• A pulsating sensation. If an abdominal aortic aneurysm becomes large enough, it can produce an annoying pulsation in the region of the navel.

Complications

When not addressed, these complications may occur.

Rupture

The major and by far the most feared complication of an aortic aneurysm is rupture. A ruptured aneurysm is most often a catastrophe, leading to massive internal bleeding. Symptoms of rupture usually begin with sudden severe pain in the chest or back, followed rapidly by palpitations, severe weakness, and lightheadedness, shock, and loss of consciousness.³

Cardiovascular collapse is usually so rapid that, even if an attempt can be made to surgically repair the rupture, mortality is excessively high. If an aortic aneurysm is to be successfully repaired, this surgery almost always must be done electively before rupture occurs.

Aortic Dissection

An aortic dissection is a tear in the lining of the aorta, which can occur in any area of weakness in the aortic wall. Flowing blood can enter the tear, forcibly separating the layers of the aortic wall. When such a dissection occurs, most often the victim will experience a sudden, severe, tearing or ripping pain in the chest or back.⁴

The internal bleeding and blood vessel damage that often results from a dissection can cause loss of consciousness, stroke, or other neurological damage, organ damage, or death. Aortic dissection can occur even if no aortic aneurysm is present, but the presence of an aneurysm makes dissection more likely.

Aortic Regurgitation

Another complication that can result from aortic aneurysm is aortic regurgitation (a leaky aortic valve).⁵ This complication can result from an aneurysm of the ascending aorta, immediately above the aortic valve.

Severe dilation of the aorta in this location can distort the aortic valve enough to cause the valve to malfunction. People experiencing this complication often have the classic signs and symptoms of aortic regurgitation, including dyspnea, chest pain, palpitations, cardiac arrhythmias, and heart failure.

Typically, it is only when these people are being evaluated for their apparent aortic regurgitation that the actual cause of the problem—an ascending aortic aneurysm—is identified.

Blood Clots

In some cases, a blood clot can form within the dilated portion of the aorta, where normal blood flow may be disrupted and areas of relative stagnation can develop. A blood clot in the aorta can embolize (break off) and travel to almost any organ in the body, often producing serious damage.

FREQUENTLY ASKED QUESTIONS

What are the warning signs of an aortic aneurysm?

The signs of an unruptured aortic aneurysm will differ according to whether it occurs in the chest (thoracic aortic aneurysm) or abdomen (abdominal aortic aneurysm). Signs of a thoracic aortic aneurysm include pain in the chest or back that appears without physical activity; hoarseness and cough; and shortness of breath. In the abdomen, an aortic aneurysm can feel like lower back pain; or discomfort, fullness, or a persistent pulsing feeling in the stomach.

What does an aortic aneurysm feel like?

Unruptured, an aortic aneurysm may not always produce symptoms. If it ruptures, however, symptoms are likely to be immediate and life-threatening, and include severe chest and back pain, weakness, and loss of consciousness.⁶

Can pain from an aortic aneurysm be intermittent?

Symptoms from an unruptured aortic aneurysm may come and go. The larger it is, the more likely it is to produce effects.⁶