How common are aneurysms ?
The majority of infrarenal aortic aneurysms are of the fusiform type. The aorta can be considered to be an aneurysm when its diameter is more than 50% bigger than the normal (expected) diameter. For men this means that the diameter has to be more than 3 cm (assuming the normal aorta is approximately 2 cm).
Aneurysms do not normally cause symptoms and, therefore, our information about how common they are comes from screening studies. Screening looks for a condition in an outwardly healthy population. An ultrasound scan is all that is necessary to diagnose it (see investigations). Because aortic aneurysms are more common in men than in women (ratio of 4 to 1) screening studies have concentrated on men over the age of 60 years.
Results from various studies have shown that:
 | 8% of men over 60 years old have aortas more than 3 cm (i.e. aneurysms) |
| 2.5 % of men over 60 years old have aneurysms more than 4 cm in size. |
The chances of having an aortic aneurysm increase if:
| you have an aneurysm elsewhere - 40% of patients with a popliteal aneurysm have an aortic one |
| you have high blood pressure |
| you have coronary artery disease or arterial disease elsewhere |
| you have a brother with an aortic aneurysm |
| you have chronic bronchitis or emphysema |
Once you have an aneurysm there is little you can do to prevent it from getting bigger (stopping smoking, controlling your blood pressure etc will help). An operation is the only way to get rid of it.
As the aneurysm grows the risk of it rupturing increases - rupture means almost certain death (around 80% will die).
Ruptured aortic aneurysms account for 1.5% of the total deaths in men over 55 years old.