An aneurysm is a localized, pathological dilation or bulge in the wall of a blood vessel. These bulges occur when the vessel wall weakens, allowing the structural integrity to fail at a specific point. The condition can affect arteries throughout the body, but is commonly noted in the aorta or cerebral arteries. The primary danger associated with an aneurysm is rupture, which involves the vessel wall tearing open and causing rapid, severe internal hemorrhage. The development of such a condition is often related to factors that compromise the elasticity and strength of the arterial tissue over time.