Aneurysm often results from atherosclerosis which results in the deposition of atheroma plaques; these deposits weaken the arterial wall. Arterial hypertension is an aggravating factor in aneurysm: the excessively high tension causes the walls of the arteries to become abnormal and especially where dehiscence occurs.
Trauma and birth defects can also be the cause of an aneurysm. Other rarer factors such as sepsis may result in the appearance of an aneurysm.
Aneurysm can cause compression of nearby organs or rupture.
For example, an aneurysm of the popliteal fossa (behind the knee) may result in compression of the nerve or venous structures that are present in the area and lead to muscle or sensory neurological disorders of the leg and foot, or venous insufficiency with risk phlebitis.
Aneurysm sometimes contains blood clots that can migrate and cause downstream arterial thrombosis.
An aneurysm can break at any time and cause a massive hemorrhage that can be very serious. The larger the aneurysm, the higher the risk of rupture.
The most dramatic ruptures of aneurysms are those of the aorta as well as the intra-cerebral arterial aneurysms, the first because their rupture is often massive; the latter because their rupture gives a hematoma that will quickly compress the brain structures that will give sometimes irreversible sequelae or cause death if vital nerve centers are affected.
