Abdominal aortic aneurysms (AAAs) affect roughly 1 in 100 adults worldwide between the ages of 30 and 79, translating to about 35 million people living with one as of 2019. That number rises sharply in older age groups and in men, where screening studies have found prevalence rates between 4% and 7.6% in men over 60.
Overall Prevalence by the Numbers
A 2022 systematic review spanning 54 studies across 19 countries estimated the global prevalence of AAA at 0.92% of all adults aged 30 to 79. That may sound small, but it covers a huge age range. Among men older than 60, population-based studies consistently find prevalence between 1.2% and 3.3%, and screening programs that specifically recruit higher-risk groups have detected rates as high as 7.6%.
Geography matters. The Western Pacific region had the highest prevalence at 1.31%, while Africa had the lowest at 0.33%. In the United States, the true prevalence remains unclear because relatively few people actually get screened. Most AAAs cause no symptoms and go undetected unless found incidentally during imaging for something else or through a targeted screening program.
Men vs. Women
AAAs are far more common in men. In screening studies of adults aged 65 to 75, prevalence runs about 9.5% in men compared to 3.2% in women, roughly a fourfold difference. One British trial found the gap was even wider: 7.6% in men versus 1.3% in women, a sixfold difference.
That said, women who do develop an AAA tend to have worse outcomes. Their aneurysms rupture at smaller diameters and they’ve been significantly underrepresented in the major clinical trials that shaped treatment guidelines. This means the evidence base for managing AAAs in women is thinner than it should be.
Who Is at Highest Risk
Three factors stand out above all others: smoking history, age, and family history.
- Smoking is the single strongest modifiable risk factor. The U.S. Preventive Services Task Force currently recommends a one-time ultrasound screening for men aged 65 to 75 who have ever smoked, even if they quit decades ago.
- Age dramatically increases risk. AAAs are rare before 50 and become increasingly common through the 60s and 70s.
- Family history carries substantial weight. Brothers of someone with an AAA have a lifetime prevalence estimated between 20% and 43%. Among identical twins, if one has an AAA, the other has about a 24% chance of developing one too, compared to roughly 5% in fraternal twins.
Other contributing factors include high blood pressure, high cholesterol, and atherosclerosis. These overlap heavily with the same cardiovascular risk profile that leads to heart attacks and strokes.
Are AAAs Becoming More or Less Common?
The answer depends on where you look. In wealthy countries like the U.S., the U.K., and Australia, death rates from aortic aneurysms have been declining, largely because smoking rates have fallen steadily over the past few decades. High-income regions saw the most significant drop in mortality, averaging about 1.8% per year between 1990 and 2021.
In lower-income countries, the trend runs in the opposite direction. Regions with low-to-middle development saw the steepest rise in aortic aneurysm deaths, increasing by as much as 278% over that same 30-year period. Smoking rates remain high in many of these countries, and access to screening and elective repair is limited. Globally, the total number of deaths from aortic aneurysms reached approximately 154,000 in 2021.
Even in the U.K., where screening programs are well established, incidence actually rose from 46 per 100,000 between 2000 and 2002 to 64 per 100,000 between 2017 and 2019, a trend linked in part to social inequalities and an aging population.
What Happens When One Is Found
Most AAAs are small when detected and don’t need immediate treatment. The standard approach is regular ultrasound monitoring to track whether the aneurysm is growing. Your aorta normally measures about 2 centimeters across; an aneurysm is defined as a bulge of 3 centimeters or more.
The traditional size thresholds that trigger a conversation about elective repair are 5.5 cm for men and 5.0 cm for women. However, recent research suggests these cutoffs may be more conservative than necessary for many patients. A modeling study found that for a 60-year-old man in average health, the optimal repair threshold to minimize aneurysm-related death was actually 6.9 cm. For a 60-year-old woman in average health, it was 6.1 cm. The difference in life expectancy between repairing at 5.7 cm versus 7.1 cm (for women) or 6.0 cm versus 7.4 cm (for men) was less than two months.
This doesn’t mean large aneurysms are safe to ignore. It means the decision about when to operate is a balancing act between the risk of rupture and the risk of surgery itself, and that balance shifts depending on a person’s age and overall health. Older patients and those in poor health generally had optimal thresholds above 7.0 cm, because for them the surgical risk is higher.
Why Screening Matters
AAAs are sometimes called a “silent killer” for a straightforward reason: they produce no symptoms until they rupture, and a ruptured AAA is fatal roughly 80% of the time. The screening test is simple, painless, and takes about 10 minutes. It’s a standard abdominal ultrasound.
The USPSTF gives a “B” recommendation (meaning there’s high certainty of moderate net benefit) for one-time screening in men aged 65 to 75 who have ever smoked. For men in that age range who have never smoked, the recommendation is more individualized. For women, there’s no blanket screening recommendation, partly because the condition is less common and partly because the evidence from major trials didn’t include enough women to draw firm conclusions.
If you have a first-degree relative (parent or sibling) who had an AAA, the case for screening is strong regardless of your smoking history. With brothers of AAA patients showing prevalence rates of 20% or higher, the genetic component is significant enough to warrant a conversation with your doctor about early imaging, particularly once you reach your mid-50s or 60s.