Most people with an abdominal aortic aneurysm, commonly called a “triple A” or AAA, have no symptoms at all. The condition is a bulging or widening of the main blood vessel that runs through your abdomen, and it’s officially classified as an aneurysm when that vessel reaches 3 centimeters or more in diameter. Because it typically grows slowly and silently, the majority of cases are found during imaging tests done for other reasons or through a targeted screening ultrasound.
What a Triple A Feels Like
In most cases, it doesn’t feel like anything. Small aneurysms rarely produce noticeable symptoms, which is exactly why they’re easy to miss. As an aneurysm grows larger, some people begin to notice a deep, constant pain in the belly or along one side of the abdomen. Back pain that doesn’t have an obvious cause is another common sign. Some people also describe a pulsing or throbbing sensation near the belly button, almost like feeling their heartbeat in their stomach.
These symptoms don’t appear in everyone, and when they do, they usually signal that the aneurysm has reached a larger size. A doctor pressing on the abdomen during a physical exam can sometimes feel a pulsating mass, but this isn’t reliable on its own, especially in people who carry more weight around the midsection.
Who Is Most at Risk
Triple A primarily affects older men, particularly those with a history of smoking. The U.S. Preventive Services Task Force defines “ever smoked” as having smoked 100 or more cigarettes in a lifetime, which includes both current and former smokers. Screening studies have found that 3 to 8 percent of the screened population has an AAA, with the vast majority of those being male. In one large study of over 81,000 men, the overall detection rate was 3.4 percent, though that number has been declining alongside smoking rates.
The risk climbs with age. Among men aged 65 to 74, the incidence is roughly 55 per 100,000 person-years, but it more than doubles for men 75 to 85 and jumps to nearly 298 per 100,000 for those over 85. Having a first-degree relative (a parent, brother, or sister) who had a triple A also raises your risk significantly.
Screening Recommendations
Because symptoms are unreliable, screening is the most practical way to find out if you have a triple A. The USPSTF recommends a one-time screening ultrasound for men aged 65 to 75 who have ever smoked. This is a painless, noninvasive test that takes only a few minutes and gives a clear measurement of the aorta’s diameter. If you fall into that category and haven’t been screened, it’s worth asking about.
For men in the same age range who have never smoked, the decision is less clear-cut, though a family history of AAA may tip the balance. For women, screening recommendations are less defined because the condition is far less common, though women who have risk factors (especially smoking history and family history) can discuss screening with their doctor.
How It’s Diagnosed
Ultrasound is the first-line tool for both screening and initial diagnosis. It’s accurate, widely available, and doesn’t involve radiation. If a pulsating abdominal mass is found on a physical exam, ultrasound is the standard next step.
When an aneurysm reaches a size that may need treatment, or if symptoms develop, a CT scan with contrast dye (called CT angiography) provides the most detailed picture. This imaging approaches 100 percent accuracy and allows doctors to map the exact location, size, and shape of the aneurysm. MRI-based imaging is an alternative for people who can’t undergo a CT scan.
What Happens After Diagnosis
Finding a small aneurysm doesn’t mean you need surgery. Most triple A’s grow slowly, averaging about 2.6 millimeters per year, though individual growth rates vary widely. The approach for smaller aneurysms is regular monitoring with ultrasound to track any changes. Typical surveillance schedules are based on the current size: every three years for an aneurysm around 3.5 centimeters, every two years at 4 centimeters, yearly at 4.5 centimeters, and every three months once it reaches 5 centimeters. These intervals are designed to catch growth well before the aneurysm reaches a size where the risk of rupture becomes a real concern.
During this monitoring period, the focus is on slowing growth. Quitting smoking is the single most impactful step, since smoking accelerates expansion. Managing blood pressure and cholesterol also helps protect the vessel wall.
When Repair Is Considered
The widely accepted threshold for elective surgical repair is 5.5 centimeters for men and 5.0 centimeters for women. Both the Society for Vascular Surgery and the European Society for Vascular Surgery endorse these cutoffs as strong recommendations. The lower threshold for women reflects that their aortas are naturally smaller, so the same relative degree of stretching occurs at a smaller absolute diameter.
That said, these thresholds aren’t one-size-fits-all. Recent analysis suggests that for healthier patients, the optimal repair point to minimize death from the aneurysm may actually be somewhat larger, while other factors like rapid growth rate (more than 5 millimeters in six months) or the development of symptoms can push the decision earlier regardless of size.
Emergency Warning Signs
A ruptured aneurysm is a life-threatening emergency. The hallmark is sudden, severe pain in the abdomen or back that doesn’t let up. This pain can radiate to the groin or legs. Some people feel lightheaded or faint, which can signal internal bleeding. If you know you have a triple A (or you’re in a high-risk group) and experience sudden, intense abdominal or back pain, call emergency services immediately. Rupture survival depends heavily on how quickly you receive treatment.