Thoracic aortic aneurysms often grow slowly. There are usually no symptoms, making them difficult to detect. Many start small and stay small, although some grow bigger over time. How quickly a thoracic aortic aneurysm may grow is difficult to predict. As a thoracic aortic aneurysm grows, signs and symptoms may include: 
Back pain
Cough
Weak, scratchy voice (hoarseness)
Shortness of breath
Tenderness or pain in the chest
 Signs and symptoms that a thoracic aortic aneurysm has ruptured or dissected include: 
Sharp, sudden pain in the upper back that spreads downward
Pain in the chest, jaw, neck or arms
Difficulty breathing
Low blood pressure
Loss of consciousness
Shortness of breath
Trouble swallowing
 Some aneurysms will never rupture or lead to dissection.