Can you explain AAA (abdominal aortic aneurysm) in simple terms?

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What is an Abdominal Aortic Aneurysm (AAA)?

An abdominal aortic aneurysm (AAA) is a balloon-like bulge in your body's main blood vessel (the aorta) that runs through your belly. 1

Understanding the Basics

The aorta is your body's largest artery - think of it as the main highway that carries oxygen-rich blood from your heart to the rest of your body. 1 It travels down through your chest and into your abdomen (belly area). 1

When the wall of this artery becomes weak, the pressure from blood flowing through can cause it to bulge out like a balloon. 1 This bulge is called an aneurysm. 1 Doctors diagnose AAA when the aorta in your belly measures 3.0 cm (about 1.2 inches) or larger in diameter. 1

Why AAA is Dangerous

The most serious danger is that the aneurysm can rupture (burst), causing life-threatening internal bleeding. 1 When this happens, 65-85% of patients die. 2

Most people with AAA have no symptoms at all until it ruptures - this is what makes it so dangerous. 1 You can't feel it or know it's there without special testing. 1 Some people may notice a pulsating feeling in their belly, but this is uncommon. 1

Who Gets AAA?

Older men who smoke or have ever smoked have the highest risk. 1 An "ever smoker" means someone who has smoked at least 100 cigarettes in their lifetime. 1

Other important risk factors include: 3, 4

  • Being over 65 years old
  • Being male
  • Having high blood pressure
  • Having a family history of AAA
  • Having heart disease or other blood vessel problems

AAA is much less common in men who never smoked and in women who have ever smoked. 1 It's rare in women who have never smoked. 1

How AAA is Found and Monitored

Screening is done with an ultrasound - a safe, painless test that uses sound waves to create a picture of your aorta. 1, 5 The technician measures the width to see if there's a bulge. 1

If a small AAA is found (less than 2 inches wide), your doctor will monitor it with repeat ultrasounds over time. 1 Small aneurysms grow slowly, typically about 1-2 mm per year. 1

Treatment Options

Surgery is generally recommended only when the aneurysm reaches 5.5 cm (about 2.2 inches) or larger, or if it's growing very quickly. 1, 5

There are two surgical approaches: 1

  • Open surgery: The surgeon removes the bulging section and replaces it with a man-made tube (graft)
  • Endovascular surgery: The surgeon inserts a metal tube (stent graft) inside the aneurysm to strengthen it, without removing the aneurysm itself

Who Should Be Screened?

Men ages 65-75 who smoke or have ever smoked should get a one-time ultrasound screening. 1, 5 This screening can reduce the risk of dying from a ruptured AAA by about half. 1

Doctors may consider screening for men ages 65-75 who never smoked, especially if they have other risk factors like family history. 1, 5

Women who have never smoked should not get routine screening because the risks outweigh the benefits. 1, 6 For women who have smoked, the evidence is currently insufficient to make a firm recommendation. 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Abdominal aortic aneurysms.

Nature reviews. Disease primers, 2018

Research

Abdominal aortic aneurysm.

American family physician, 2015

Research

Abdominal aortic aneurysm: A comprehensive review.

Experimental and clinical cardiology, 2011

Guideline

Abdominal Aortic Aneurysm Screening Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Abdominal Aortic Aneurysm Screening Guidelines for Women

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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