An abdominal aortic aneurysm is defined as:

• A. A normal abdominal aorta
• B. A swollen artery in the leg
• C. Aneurysm due to infection
• D. Enlarged aorta with rupture risk

Answer: (D)

An abdominal aortic aneurysm is a localized, permanent enlargement of the abdominal aorta. The defining feature is that the aorta becomes enlarged, which increases the tension on the vessel wall and raises the risk of rupture. That rupture risk is the critical clinical concern and guides management, from monitoring small aneurysms to planning surgical repair for larger ones. It’s not a normal aorta, not a swollen artery in the leg, and not necessarily caused by infection (that would be a mycotic aneurysm). In practice, an aneurysm is typically considered present when the aorta exceeds about 3 cm in diameter or is substantially larger than normal, with rupture risk increasing as size grows.