Abdominal Aortic Aneurysm Screening: Who Benefits From an Ultrasound

You recently turned 65, and your clinician mentioned a belly ultrasound to check your aorta. You may never have heard of an abdominal aortic aneurysm. Or a friend had one repaired and you wonder if you should be checked. This guide explains what the condition is, who benefits from screening, and what the results mean.

What an abdominal aortic aneurysm is

The aorta is the largest artery in your body. It carries blood from the heart down through the chest and belly. An abdominal aortic aneurysm (AAA) is a weak spot where the aorta in the belly bulges outward [4].

• Most aneurysms grow slowly and cause no symptoms.
• If an aneurysm bursts (ruptures), it causes severe internal bleeding. Many people with a rupture die, even with emergency surgery.
• The larger the aneurysm, the higher the risk of rupture.

This is why finding an aneurysm before it bursts can save lives.

Who is at risk

The main risk factors are [1][4]:

• Smoking, now or in the past. This is the strongest risk factor.
• Male sex.
• Age 65 and older.
• A parent or sibling who had an AAA.
• High blood pressure, high cholesterol, and other artery disease.

How screening works

Screening uses a simple ultrasound of the belly. It is quick, painless, and uses no radiation. For most people, screening is done only once [1][2].

The aorta is measured across its width.

• Below 3.0 cm: normal.
• 3.0 cm or larger: an aneurysm.

What your doctor looks at: who should be screened

US guidance

The US Preventive Services Task Force (USPSTF) 2019 recommendation [1]:

• Men aged 65 to 75 who have ever smoked: one-time ultrasound screening (grade B).
• Men aged 65 to 75 who have never smoked: offer screening selectively, based on history and values, because the benefit is small (grade C).
• Women aged 65 to 75 who have ever smoked or have a family history of AAA: not enough evidence to decide (an "I" statement).
• Women who have never smoked and have no family history: do not screen routinely (grade D).

"Ever smoked" usually means 100 or more cigarettes in your lifetime.

Canadian guidance

The Canadian Task Force on Preventive Health Care 2017 guideline [2]:

• Men aged 65 to 80: one-time ultrasound screening.
• Men over 80: do not screen.
• Women: do not screen.

The Canadian Task Force did not make a separate recommendation for people who smoke, because there was no trial evidence on screening smokers alone [2]. It ended its mandate in March 2026, and the guideline remains posted for reference.

The key differences

• Age range: 65 to 75 in the US, 65 to 80 in Canada.
• Smoking: the US focuses on men who have ever smoked. The Canadian guideline included all men 65 to 80.
• Women: both advise against routine screening for women at low risk. The US says evidence is unclear for women who smoked.

The evidence

Large trials in men aged 65 and older found that one-time ultrasound screening lowers the risk of aneurysm rupture and death from AAA [2][3]. Screening also leads to more planned repairs, some of which may be for aneurysms that would never have burst. The number of aneurysms found in screening has fallen as fewer people smoke, which lowers the absolute benefit today [2].

If an aneurysm is found

Most screen-detected aneurysms are small. Management depends on size and growth.

• Small aneurysms: watched with repeat ultrasound. Larger ones are checked more often.
• Large aneurysms: repair is usually discussed when the aneurysm reaches about 5.5 cm in men, or a little smaller in women, or grows quickly.
• Repair options include open surgery or a stent placed through the arteries in the groin (endovascular repair).

Your clinician will also focus on reducing growth and heart risk. That often means stopping smoking, controlling blood pressure, and treating cholesterol.

Living with a small aneurysm

Learning that you have an aneurysm can be frightening. But most small aneurysms grow slowly, often by a few millimetres a year, and many never need repair.

• Keep your follow-up scans. They are the main safety net.
• If you smoke, quitting is the most important step, because smoking speeds growth.
• Stay active. Most normal daily activity is safe. Ask your clinician about very heavy lifting.
• Tell any new clinician that you have an aneurysm.

Questions to ask your clinician

• Do I qualify for AAA screening based on my age, sex, and smoking history?
• Does my family history change the advice for me?
• Is the ultrasound covered where I live?
• If an aneurysm is found, how often will it be checked?
• At what size would repair be considered for me?
• What can I do to lower the chance it grows?

When to get care quickly

Call 911 right away if you have:

• Sudden, severe pain in the belly or lower back, especially if it feels tearing or ripping.
• Pain with dizziness, fainting, a fast heartbeat, or cold, clammy skin.
• A known aneurysm and any new, severe belly or back pain.

A ruptured aneurysm is a life-threatening emergency.

Bottom line

An abdominal aortic aneurysm is a silent bulge in the body's main artery. A single painless ultrasound can find it. The US recommends one-time screening for men 65 to 75 who have ever smoked. Canada's task force recommended it for all men 65 to 80. Most aneurysms found are small and are watched, not repaired right away.

Primary AI can show you the guideline and study sources behind this topic in plain language, so you can bring better questions to your appointment.