The aorta, the body's main artery, supplies oxygen-rich blood from your heart to every part of your circulatory system.
There are two primary disorders that affect the aorta:
- An aortic aneurysm, which means a bulge in the wall of the vessel. ("Aneurysm" comes from a Greek word meaning "to widen out.")
- An aortic dissection, which means a split, tear, or weakened area in the lining of the vessel. ("Dissection" comes from a Latin word meaning "to cut apart.")
(There are also disorders of the aortic valve, which controls the flow of blood from your heart into your aorta.)
Aneurysms and dissections can occur in any of the aorta's three parts: the ascending aorta, which extends upward from your heart's left ventricle to the aortic arch; the arch, which curves up and over the top of your heart; and the descending aorta, which extends from your aortic arch down through your chest and abdomen, where it splits into two branches that run down your legs. The aorta is also classified into the thoracic aorta (the parts in your chest—the ascending aorta, the aortic arch, and the part of the descending aorta above your diaphragm) and the abdominal aorta (the part of the descending aorta below your diaphragm).
A dissection allows blood to flow between the layers of the aortic wall, which can lead to an aneurysm. Or an aneurysm can sometimes lead to a dissection. Either a dissection or a large aneurysm may rupture—an event that often is fatal.
About 13,000 people in the U.S. die every year from a ruptured or dissected aorta, according to the National Institutes of Health. Dissections are more common in men than in women, and the risk of both dissection and aneurysm rises with age. But if these conditions are detected early, they can often be successfully treated with medication or surgery.
Symptoms of a disease are indications that can be detected by the patient, such as pain or fatigue (while signs are indications that can be detected by a doctor, such as the results of a blood test or an X-ray). One of the problems with diagnosing either thoracic or abdominal aneurysms at an early stage is that they often develop very slowly, over many years, and may cause few signs or symptoms.
If symptoms of a thoracic aortic aneurysm (TAA) do occur, they may include pain in your jaw, neck, back or chest; coughing or hoarseness; or trouble breathing or swallowing.
And if symptoms of an abdominal aortic aneurysm (AAA) do occur, they may include a throbbing sensation in your abdomen, a deep pain in the side of your abdomen or your back, or a gnawing pain in your abdomen that lasts for several hours or days. But it is estimated that as many as 1.5 million Americans have an undiagnosed AAA.
The symptoms of a serious aortic dissection usually come on suddenly and typically start with severe chest pain that's often described as stabbing or tearing. Symptoms of an aortic dissection may also include pain in your shoulder, neck, arm, jaw or abdomen; fainting or dizziness; heavy sweating; nausea or vomiting; rapid or weak pulse; and trouble breathing or swallowing.
The symptoms of a ruptured aneurysm are similar—sharp, severe pain and sometimes other symptoms as well, including nausea, vomiting, clammy skin or light-headedness.
In either case, the resulting internal bleeding causes your blood pressure to drop dramatically, depriving your internal organs of the blood they need to function and sending your body into shock. An aortic dissection or a ruptured aortic aneurysm is usually fatal unless operated on and repaired as soon as possible.
The aorta in an average adult is about three feet long and more than an inch in diameter. Every single ounce of the five to six quarts of blood that your heart pumps each minute passes through your aorta. If the vessel is damaged by disease or injury, then the pressure exerted by the blood as it travels through the aorta can eventually cause a dissection or aneurysm.
Among the factors that can damage the aorta are smoking, atherosclerosis in the coronary arteries (a narrowing and stiffening of the arteries that supply blood to the heart), hypertension (high blood pressure), or untreated infections. Conditions such as obesity or diabetes increase your risk of having an aneurysm or dissection, and their incidence also rises with age. In addition, TAAs are associated with certain genetic conditions, such as Marfan syndrome. Trauma to the chest or abdomen, such as from a car accident, can also cause an aneurysm or dissection.
Once an aneurysm develops, it won't go away on its own—though small aneurysms may remain stable over a period of time. But some aneurysms, especially larger ones, grow over time. Dissections as well almost never resolve on their own.
A symptomless aortic aneurysm is most likely to be discovered when your doctor examines the results of a test done for some other purpose, such as a chest X-ray or a CT scan. A symptomless aneurysm may also be discovered by chance during a routine physical exam. For example, an AAA may be detected due to subtle changes in the sound of the abdominal blood flow through a stethoscope. And a dissection may be suspected based signs such as on a heart murmur (a “swooshing” sound perceptible through a stethoscope), a discrepancy in the blood pressure of one arm compared to the other or a delay in the pulse of your legs compared to your arms.
A thorough medical and family history may also lead your doctor to consider the possibility of an aortic aneurysm or dissection.
If the presence of an aneurysm or dissection is suspected, certain diagnostic tests will likely be conducted. They may include an echocardiogram (an ultrasound image of your chest or abdomen); a CT scan; a magnetic resonance image (MRI); or an angiogram (also referred to as cardiac catheterization), which uses opaque dye to image your cardiovascular system. The results of the tests may help your doctor determine the location and size of an aneurysm or dissection.
A very small, symptomless aneurysm (less than about 1.6 inches in diameter) may not require treatment, just monitoring. The size of the aneurysm will determine how often regular testing should occur.
If your aneurysm grows larger than 1.6 inches or begins to cause symptoms, your doctor may recommend medication aimed at lowering your blood pressure or relaxing the walls of your blood vessels; this may lessen the chance that the aneurysm will rupture. And in other cases, especially if an aneurysm is large or growing quickly, surgery may be indicated.
A dissection of the descending aorta will often be treated with medication aimed at lowering your blood pressure or relaxing the walls of your blood vessels. But for a dissection of the ascending aorta, emergency surgical repair is almost always required.
Page reviewed on: Jun 26, 2015
Page reviewed by: Jock McCullough, MD
- About Us
- About Your Heart
- Conditions We Treat
- Treatments We Use
- Patient Testimonials
- Our Team
- Information for Patients
- Information for Health Professionals