What can cause a person to have an aneurysm?

Risk factors: True aneurysm are generally idiopathic or has no true risk factor cause relationship but they have risk factors like high blood pressure, high cholesterol, smoking , bicuspid aortic valve, atherosclerosis and peripheral arterial disease and coronary artery disease, patients with Marfan syndrome and ehler danlos syndrome type 4 are at high risk. In some cases infection of the artery can cause it.