Age plays an important part in the causes of aortic dissection. Among older people, aortic dissection is much more likely to be associated with other forms of heart disease, such as high blood pressure or atherosclerosis. High blood pressure occurs when the blood pushes against the arterial wall with too much force, while atherosclerosis is a disease characterized by plaque deposits that form in the arteries, resulting in narrowed, stiffened arteries. Among younger people, these are rare causes of aortic dissection (less than 35 percent of total cases). Other possible factors that may cause and/or precipitate aortic dissection, especially among younger people include:

• Existing aortic aneurysm. This occurs when a part of the aorta wall weakens and bulges out.
  
  
• Aortic stenosis. A congenital or acquired condition in which the blood flow from the heart to the aorta is reduced by a narrowed (stenotic) aortic valve, which rests between the left ventricle and the aorta. The valve leaflets may be fused or narrowed, or the valve itself may be too small. Bicuspid aortic valve is a congenital anomaly that may be associated with aortic stenosis and dissection.
  
  
• Coarctation of the aorta. A congenital condition in which the aorta is pinched, constricted or narrowed at some point along its length.
  
  
• Valvular regurgitation. A condition in which one or more of the heart’s four valves do not close properly, allowing blood to leak back into the chamber from which it came.
  
  
• Pregnancy. Being pregnant places additional strain on a woman’s heart and increases the risk of an aortic dissection.
  
  
• Diseases that affect collagen, which is a major component of connective tissue. These diseases include Marfan syndrome, Ehlers-Danlos syndrome and others.
  
  
• Inflammatory diseases that affect the blood vessels, such as Takayaso arteritis, giant cell arteritis, rheumatoid arthritis and syphilis associated with an inflamed aorta.
  
  
• Turner syndrome. A syndrome that affects women, causing underdeveloped and infertile ovaries. Coarctation of the aorta is not uncommon.
  
  
• Trauma. Chest trauma, such as occurs during a car accident and the person is slammed into the steering wheel, can cause aortic dissection.
  
  
• High intensity weight lifting can occasionally cause aortic dissection because of rapid and transient increases in blood pressure.
  
  
• Cocaine use. Cocaine can cause a rapid rise in blood pressure, which may then result in a tear of the lining of the aorta. The mortality rate from aortic dissection among cocaine users is nearly twice that of nonusers.

An aortic dissection can occur in any individual, but the condition is seen three times more often in men than women, and people with a family history of aortic dissection are generally at higher risk. Women are more likely to die from aortic dissection as compared to men, according to results of a study completed in 2004. Women also may have different symptoms, which may cause them to delay treatment.