Abdominal Aortic Bruit: Auscultation, Causes and Significance

A vascular auscultation guide for students, nurses and residents · Updated 2026

To listen for an abdominal aortic bruit, place the diaphragm in the midline epigastrium just below the xiphoid and move down the line of the aorta to the umbilicus, then listen over the renal arteries (2 to 3 cm above and lateral to the umbilicus), the iliac arteries (lower quadrants) and the femoral arteries (groin, just below the inguinal ligament). Always auscultate before palpation. An abdominal bruit is a whoosh of turbulent flow that usually means aortic atherosclerosis, an aneurysm or stenosis of a branch vessel, although a soft systolic epigastric bruit is common and benign in thin young adults.

Abdominal vascular auscultation: the routine

Abdominal auscultation covers two things, bowel sounds and vascular sounds. Do the vascular part with the diaphragm (the bell also works) applied lightly, patient supine with knees slightly bent, in a quiet room. Listen for several cardiac cycles at each site and decide whether any bruit is systolic only or continues into diastole.

The bowel sounds guide covers the other half of abdominal auscultation.

What an abdominal bruit sounds like

A low to medium pitched whoosh or blowing sound timed with the pulse, easiest to hear in the epigastrium where the aorta is closest to the surface. It is softer than most carotid bruits and easily masked by bowel sounds, which is one reason to listen before you stir the bowel by palpating.

• Systolic bruit. The common pattern. In an older patient with risk factors it points to atherosclerosis somewhere in the aorta or its branches; in a lean 20-year-old it is usually a flow sound.
• Continuous (systolic-diastolic) bruit. The gradient persists through diastole. Think tight stenosis, arteriovenous fistula, or renal artery stenosis if it lateralizes to an upper quadrant.
• Bruit that changes with breathing. A bruit that gets louder on expiration in the epigastrium is the classic clue to celiac artery compression.

Causes of an abdominal bruit

• Aortic atherosclerosis and stenosis. The commonest pathological cause in older adults, often with weak femoral pulses and claudication.
• Abdominal aortic aneurysm (AAA). Turbulence in the dilated segment can produce a bruit, but only in a minority of aneurysms. A normal auscultation does not exclude an AAA; a widened pulsatile mass on light palpation is more informative, and ultrasound is definitive.
• Renal artery stenosis. Suspect it when the bruit is lateralized, high-pitched or continuous, particularly in a hypertensive patient. See the renal artery bruit guide.
• Chronic mesenteric ischemia. Postprandial pain, food fear and weight loss in a vasculopath; an epigastric bruit is present in a proportion of cases.
• Celiac artery compression (median arcuate ligament syndrome). Typically a young, thin patient with postprandial pain and an epigastric bruit that varies with respiration, loudest in expiration.
• Hepatic bruit. A bruit over the liver in hepatocellular carcinoma, alcoholic hepatitis or a hepatic AV malformation. A continuous venous hum over the liver suggests portal hypertension instead.
• Splenic AV fistula or aneurysm. Rare; continuous bruit in the left upper quadrant.
• Benign flow bruit. Soft, midline, systolic only, in a thin young person without hypertension or risk factors. Prevalence estimates range from a few percent to around a quarter of healthy young adults depending on the study.

Safety: bruit, pulsatile mass and suspected AAA

A mid-abdominal bruit in an older patient, especially with a wide pulsatile mass, abdominal or back pain, or hypotension, should make you think of an abdominal aortic aneurysm until imaging says otherwise. Do not palpate deeply over the mass. Light palpation to estimate width is acceptable in a stable patient; deep or repeated palpation of a possibly leaking aneurysm is not.

The classic nursing exam question reads: "The nurse auscultates a mid-abdominal bruit in a patient. What should the nurse do?" The answer is to stop palpating, avoid deep palpation of the abdomen, and notify the provider, because the bruit may indicate an aneurysm. Document the finding, assess for a pulsatile mass with light touch only, check for pain and peripheral pulses, and anticipate an abdominal ultrasound. The wrong answers are to press harder to characterize the mass or to record the bruit as a normal variant without escalation.

Systolic vs continuous: what the timing tells you

Timing carries more information than loudness. A purely systolic epigastric bruit in a young person is usually benign; the same sound in an older vasculopath signals atherosclerosis but not where or how severe. A systolic-diastolic bruit tells you a pressure gradient exists throughout the cycle, which narrows the field to severe stenosis, an AV connection or renal artery disease, and it should always prompt imaging. Very tight stenosis, above roughly 90 percent, can fall silent as flow drops, so a quiet abdomen is never proof of a healthy aorta.

Next steps

Abdominal ultrasound is the first test for a suspected aneurysm and for screening the aorta in older men and smokers. Renal duplex, or CT/MR angiography, evaluates a suspected renal or mesenteric lesion. A bruit in a patient with vascular risk factors should also prompt an ankle-brachial index and a review of statin, antiplatelet and blood pressure therapy, since the bruit is a marker of atherosclerosis beyond the abdomen.

Documentation

State where, when in the cycle and what you excluded. For example: "Soft systolic bruit midline epigastrium, no diastolic component, no lateralization, aorta of normal width on light palpation, femoral pulses equal and no femoral bruit." Or: "Bruit over mid-abdomen with widened pulsatile mass; deep palpation deferred; provider notified; ultrasound requested."

FAQ

What is an abdominal bruit?

A whooshing or blowing sound heard over the abdomen, produced by turbulent flow in the aorta or one of its branches. It usually reflects atherosclerotic narrowing, an aneurysm, renal or mesenteric stenosis or a vascular liver lesion, though a soft systolic bruit is also common in healthy thin young adults.

Where do you listen for abdominal bruits?

Midline epigastrium just below the xiphoid down to the umbilicus for the aorta, 2 to 3 cm above and lateral to the umbilicus for the renal arteries, the lower quadrants for the iliacs and the groin below the inguinal ligament for the femorals. Use the diaphragm lightly and auscultate before palpating.

What causes an abdominal bruit?

Aortic atherosclerosis or stenosis, abdominal aortic aneurysm, renal artery stenosis, chronic mesenteric ischemia, celiac artery compression, hepatic tumors or alcoholic hepatitis, and splenic AV fistula. A benign flow bruit in a thin young person is the commonest cause of all.

What does an abdominal bruit sound like?

A soft, low to medium pitched whoosh timed with the pulse, easiest to hear in the epigastrium. Most are systolic only; a bruit that continues into diastole points to a tight stenosis, an AV fistula or renal artery stenosis and deserves imaging.

The nurse auscultates a mid abdominal bruit in a patient. What should the nurse do?

Stop palpating, avoid deep palpation over the area, and notify the provider, because a mid-abdominal bruit may indicate an abdominal aortic aneurysm. Document the finding, use light touch only to check for a pulsatile mass, assess pain and peripheral pulses, and anticipate an ultrasound.

Does an abdominal aortic aneurysm cause a bruit?

Only in a minority of cases. Most aneurysms are silent on auscultation, so a normal exam does not exclude one; a widened pulsatile mass is more useful and ultrasound is definitive.