When an aneurysm occurs in the part of the aorta that runs through the chest, it’s called a thoracic aortic aneurysm (TAA). Thoracic aortic aneurysms occur most often in the descending thoracic aorta (50 percent of the time) followed by the ascending aorta (25 percent of the time) and the aortic arch (25 percent of the time).

In the early stages, when a TAA is small, it may not pose an immediate health risk. Patients may want to have their doctor monitor the condition regularly. If the TAA continues to grow, the aorta’s walls become thin and lose their ability to stretch. The weakened sections of the aortic wall may become unable to support the force of blood flow. Such an aneurysm could burst, causing serious internal bleeding.

What are the symptoms?
Many people don’t feel any symptoms, but when a thoracic aortic aneurysm becomes large and begins to leak or expand, they may feel the following symptoms caused by pressure from the aorta on surrounding organs:

• Back or chest pain
• Hoarse cough
• Difficulty breathing or swallowing
• Swelling in the neck and arms
• Horner’s syndrome (drooping eyelid, constricted pupil
  and dry skin on one side of the face)

If an aneurysm grows to the point of rupture, people may experience the following symptoms:

• Dizziness
• Fainting
• Rapid heartbeat
• Sudden weakness

People who experience any of the symptoms listed above should call their doctor immediately.

TAAs are often discovered during an examination for other medical reasons. Most often, aneurysms are found during a medical test such as a CT scan, ultrasound or angiogram.

What are the causes?
Over time, vascular disease, injury or a hereditary defect of tissue within the arterial wall can cause the aorta to weaken. Blood pressure against the weakened area can cause it to stretch and grow thinner, like a balloon.

Risk factors for developing an aneurysm include:

• Smoking
• Heart disease
• High blood pressure
• Trauma to the aorta, such as injury due to a car accident
• Rare genetic conditions such as Marfan’s syndrome or Ehlers-Danlos syndrome

Prevention
There are several ways to reduce the likelihood of developing an aortic aneurysm:

• Do not smoke
• Control blood pressure
• Control cholesterol levels
• Exercise regularly