Why can a true aneurysm be dangerous?

A true aneurysm is a localized dilation of a blood vessel that involves all three layers of the vessel wall. The danger associated with a true aneurysm primarily stems from the potential for rupture. When an aneurysm ruptures, it can lead to a significant and rapid loss of blood, which can be life-threatening. This is due to the sudden opening of the blood vessel, allowing blood to spill out into the surrounding area, which can cause internal bleeding.

The risk of rupture is influenced by several factors, including the size of the aneurysm and the pressure within the vessel. As the aneurysm grows, the tension on the vessel wall increases, elevating the likelihood of a rupture. When an aneurysm does rupture, it can lead to severe complications, such as shock or even death, if not addressed immediately.

This highlights the critical nature of monitoring and managing true aneurysms, as timely intervention is essential to prevent catastrophic outcomes. The other options presented do not reflect the immediate life-threatening nature of a rupture, making option D the most significant and relevant concern associated with true aneurysms.