The aorta is the largest artery in the body, carrying blood from the heart down through the chest and abdomen before branching into the legs. When a section of the aorta within the abdomen weakens and bulges outward, it forms an abdominal aortic aneurysm (AAA). These aneurysms grow slowly and silently — and if they rupture, the result is catastrophic internal bleeding that is fatal in more than 80 percent of cases.
Why AAA Is Called a Silent Killer
Most abdominal aortic aneurysms cause no symptoms whatsoever. A person can walk around for years with an enlarging aneurysm and feel completely normal. Occasionally, a larger aneurysm may produce a pulsating sensation in the abdomen, deep back pain, or flank discomfort — but these are often dismissed or attributed to other causes.
If you experience sudden, severe abdominal or back pain, dizziness, or rapid pulse — especially if you have known risk factors for AAA — call 911 immediately. These can be signs of rupture.
Risk Factors for AAA
Certain factors significantly increase the likelihood of developing an abdominal aortic aneurysm.
- —Male sex — men are 4 to 6 times more likely to develop AAA than women
- —Age 65 or older
- —Smoking history — by far the strongest modifiable risk factor
- —Family history of AAA in a first-degree relative
- —High blood pressure (hypertension)
- —Atherosclerosis (hardening and plaquing of the arteries)
- —History of other aneurysms elsewhere in the body
- —Connective tissue disorders such as Marfan or Ehlers-Danlos syndrome
Current Screening Recommendations
The U.S. Preventive Services Task Force (USPSTF) recommends a one-time abdominal ultrasound screening for all men aged 65 to 75 who have ever smoked (defined as 100 or more cigarettes in their lifetime). Many vascular surgeons and cardiologists extend this recommendation to those with a family history of AAA, even if they have never smoked.
For aneurysms that are detected but not yet large enough to require intervention, surveillance ultrasounds are performed at regular intervals (typically every 6 to 12 months) to track growth over time.
What the Ultrasound Looks For
An abdominal aortic ultrasound measures the maximum diameter of the aorta at multiple points. The normal aortic diameter in adults is under 3 centimeters. An aorta between 3.0 and 5.4 cm is considered a small-to-moderate aneurysm and is typically managed with watchful waiting and risk factor control.
- —Aorta < 3.0 cm: normal — no aneurysm
- —Aorta 3.0–5.4 cm: aneurysm present — surveillance recommended
- —Aorta ≥ 5.5 cm: large aneurysm — surgical repair consultation typically recommended
- —Rapid growth > 0.5 cm in 6 months: may prompt earlier intervention
Treatment When an Aneurysm Is Found
For small aneurysms, treatment focuses on reducing growth and rupture risk: controlling blood pressure, quitting smoking, managing cholesterol, and regular surveillance imaging. For larger aneurysms, endovascular aneurysm repair (EVAR) — a minimally invasive stent-graft procedure — or open surgical repair may be recommended.
One-time AAA screening ultrasound is available at Heartwell STAT Imaging with same-day results. If you are over 65 and have a history of smoking or a family history of aortic aneurysm, now is the time to get screened.