Abdominal Aortic Aneurysm (AAA) - What You Need to Know
A quick, printable guide to understand AAA size, risk, and when to act.
Patient education
AAA = a bulge in the main belly artery (aorta)Most AAAs grow slowly and are watched safelyRisk rises as size increasesRupture is an emergency
1) What is an AAA?
An abdominal aortic aneurysm (AAA) is when the aorta (the body’s main artery) becomes enlarged in the belly.
Think of it like a weak spot in a garden hose that starts to bulge.
Many people feel no symptoms. AAAs are often found on an ultrasound or CT scan done for another reason.
Common risk factors
Age (especially 65+)
Smoking history (biggest driver)
High blood pressure
Family history of AAA
Male sex (women can still have AAA)
When to call 911 now
Sudden severe belly, back, or flank pain, fainting, or collapse can be signs of rupture.
Do not drive yourself. Call 911.
2) The key idea: risk is per year
When you see a number like “15% per year,” it means:
if 100 similar people had the same size aneurysm and did not treat it, about 15 would be expected to rupture over the next 12 months.
This is an average for groups, not a personal prediction. Your risk can be higher or lower depending on growth rate,
smoking, blood pressure, and other factors.
How to read: each point is a group of 100 similar people with that aneurysm size.Note: this is annual (1-year) risk, not lifetime risk.
These are teaching estimates. Your clinician uses your imaging, growth rate, and overall health to personalize recommendations.
3) How AAAs are usually managed
Situation
Typical plan
Small AAA Often found on screening ultrasound
Watch with periodic imaging. Control blood pressure. Stop smoking.
Growing AAA Size increases over time
Closer follow-up imaging. Referral to vascular surgery may be recommended.
Larger AAA Risk of rupture is higher
Discuss repair options (endovascular or open) based on size, anatomy, and surgical risk.
What you can do today
Do not smoke (stopping is one of the biggest risk reducers).
Keep blood pressure controlled.
Take prescribed meds (like statins) if recommended.
Keep follow-up imaging appointments.
Tell family members if there is a strong family history.
Questions to ask
What is my aneurysm size in cm?
Has it changed since last imaging?
How often should I repeat imaging?
At what size do you recommend surgical discussion?
Do I need a vascular surgery consult now?
4) Repair options in plain terms
If repair is recommended, there are two common approaches. Your vascular surgeon decides what fits your anatomy and health.
Endovascular repair (EVAR) - a stent graft is placed through small groin incisions. Recovery is often faster, but long-term imaging follow-up is important.
Open repair - the aneurysm is repaired through an abdominal incision. It is a bigger operation with longer recovery, but can be durable.
Bottom line
Many AAAs can be watched safely for years. The goal is to choose the right time to intervene, before rupture risk becomes unacceptably high.
If you have sudden severe pain, fainting, or feel very ill, treat it as an emergency and call 911.
References (evidence base)
UK Small Aneurysm Trial Participants. Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. Lancet. 1998;352:1649-1660.
Lederle FA, Wilson SE, Johnson GR, et al. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med. 2002;346(19):1437-1444.
Sweeting MJ, Thompson SG, Brown LC, Powell JT; RESCAN Collaborators. Meta-analysis of individual patient data to examine factors affecting growth and rupture of small abdominal aortic aneurysms. Br J Surg. 2012;99(5):655-665.
Society for Vascular Surgery. Patients with Abdominal Aortic Aneurysm (AAA) - practice guideline recommendations (elective repair thresholds). Vascular.org.
The rupture-risk values shown are teaching estimates derived from cohort data and meta-analyses. Individual risk varies by aneurysm anatomy, sex, growth rate, smoking, and blood pressure.
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