 A minority of aneurysms are caused by copper deficiency, which results in a decreased activity of the lysyl oxidase enzyme, affecting elastin, a key component in vessel walls.Copper deficiency results in vessel wall thinning, and thus has been noted as a cause of death in copper-deficient humans, chickens and turkeys

Aneurysmal blood vessels are prone to rupture under normal blood pressure and flow due to their special mechanical properties that make them weaker.To better understand this phenomenon, we can first look at healthy arterial vessels which exhibit a J-shaped stress-strain curve with high strength and high toughness (for a biomaterial "in vivo").