Aortic Aneurysm, Dissection And Rupture

The main artery in your body is called the aorta which carries oxygen-rich blood away from your heart to the rest of your body and your brain. An aortic aneurysm is a swelling or bulging of the aorta.

Diseases of the aorta can be very serious, and potentially life-threatening.  

What Is An Aortic Aneurysm?

An aortic aneurysm is a swelling or bulging at any point along the aorta. The types of aortic aneurysm are divided according to where they occur.

The most common place is in the abdomen (your tummy area) called an abdominal aortic aneurysm or AAA for short. Less frequently, an aneurysm can occur in the chest and is called a thoracic aortic aneurysm or TAA for short.

Small or moderate sized aortic aneurysms are unlikely to cause you any symptoms, and can be difficult to detect. Larger aneurysms may cause discomfort or pain in your chest or back dependent on the location of the aneurysm.

Blood is under pressure when it’s pumped from your heart into the aorta. The wall of this artery has to be strong enough to resist this pressure, but still flexible enough to return to its normal shape after a pulse of blood has passed through.

An aneurysm or a bulging of the aorta usually occurs where the wall has become weak and has lost its elastic properties, so it doesn’t return to its normal shape after blood has passed through. 

There is no specific cause for developing an aortic aneurysm, but the risk factors include:

  • age, your risk increases as you get older
  • high blood pressure
  • smoking
  • atherosclerosis – fatty build up in arteries
  • family history of aortic aneurysm
  • genetic conditions such as Marfan syndrome. 


Aneurysms are difficult to diagnose. There can be no symptoms and sometimes they are discovered during tests for other conditions commonly by ultrasound, CT or MRI scans. There is also a specific screening programme in place for abdominal aortic aneurysm.

The treatment you receive will depend on a number of factors, such as the size of the aneurysm and the location. A CT scan can be requested in order to assess the aneurysm.

If you have an aortic aneurysm there is a risk that it may begin to leak or even burst. The bigger the aneurysm is, the higher the risk of it bursting (rupture). If it grows more than around 5.5cm you may need to have surgery to prevent it from bursting. A specialist will discuss which treatment is best for you.

Aortic dissection is when the weakened wall of the aorta tears, causing blood to leak between the layers that makes up the wall. This can happen suddenly or slowly over time. If you have an aortic aneurysm you are higher risk of this happening. 

The symptoms of aortic dissection include:

  • a sudden onset of severe pain across the chest, often felt in the back or between the shoulder blades
  • pain in the jaw, face, abdomen, back or lower extremities
  • feeling cold, clammy and sweaty
  • fainting and shortness of breath.


If you experience any of these symptoms you should phone 999 immediately as aortic dissection is a medical emergency and needs urgent treatment.

Conditions that weaken the aorta wall, like an aneurysm, can make aortic dissection more likely.

High blood pressure is one of the most common risk factors. Over a long period of time high blood pressure can weaken the wall of the aorta, making it more likely to tear. 

Some people are born with a condition that causes the aorta wall to weaken. These conditions are uncommon and include Marfan syndrome, and bicuspid aortic valve. 

There are two types of aortic dissection, Type A and Type B. Each type is located in a different area and the treatment and management of each is different.

  • Type A occurs in the arch and proximal descending aorta (the area from the left ventricle to the aortic arch). The risk of rupture is high, and usually requires surgery to repair the aorta and possibly replace the aortic valve. 
  • Type B occurs in the descending aorta. The risk of rupture is less than for Type A, and doesn’t always require immediate surgery. Doctors may be able to keep the condition under control with the use of blood pressure lowering medicines. 
All people who have aortic dissection (including those treated surgically) will have to take medication to control their blood pressure, usually for the rest of their lives. The medication helps reduce stress on the aorta.

Aortic rupture is when all the layers of the aorta wall tear, causing blood to leak out from the aorta often due to a large aortic aneurysm that bursts. This will stop blood being pumped around the body and is life threatening. 

Ideally an aortic aneurysm will be repaired before a rupture can occur.