An aneurysm is a localized, abnormal dilation of a blood vessel, usually an artery, that is greater than 1.5 times the normal diameter of the vessel.

True aneurysm: involves all three layers of the vessel wall (intima, media, and adventitia).
False aneurysm (pseudoaneurysm): involves only the outer two layers of the vessel wall (media and adventitia), with the intima being absent.
Aneurysm in situ: occurs within a single segment of a vessel.
Aneurysm of an anastomotic site: occurs at the site of an anastomosis between two vessels.

Atherosclerotic aneurysm
- Most common type of aneurysm
- Associated with atherosclerosis and hypertension
Traumatic aneurysm
- Caused by trauma to the vessel wall
- May be caused by a penetrating injury or a deceleration injury
Inflammatory aneurysm
- Caused by inflammation of the vessel wall
- May be caused by conditions such as Takayasu arteritis or giant cell arteritis
Dissecting aneurysm
- Caused by a tear in the intima of the vessel wall
- May be caused by conditions such as hypertension or atherosclerosis
Mycotic aneurysm
- Caused by an infection of the vessel wall
- May be caused by conditions such as endocarditis or sepsis

Medical management: to control hypertension and prevent further growth of the aneurysm
Surgical management: to repair or replace the affected vessel
Endovascular management: to repair or replace the affected vessel using a minimally invasive procedure

ANEURYSM