Bruit

A bruit is an abnormal sound heard through auscultation, produced by turbulent blood flow within a vessel or the heart. The term is used mainly in vascular and cardiovascular exams and is often associated with areas where arteries may be narrowed or irregular. In clinical practice, carotid, abdominal aortic, renal, and femoral bruits are among the most commonly evaluated examples. Bruits result from increased velocity and disturbed flow as blood encounters stenosis, aneurysm, arteriovenous fistula, or high-output states. They are typically low to medium frequency sounds and are distinct from heart murmurs.

Detection and interpretation rely on careful auscultation with a stethoscope. The examiner listens over the suspected vessel, often one side at a time, sometimes with the patient holding their breath briefly to reduce lung noise. Bruits do not always correlate with the degree of vascular disease and can occur in people without significant stenosis, while some significant lesions may be quiet, especially in certain locations or in obese patients. Bruits can also be confused with venous hums or transmitted heart sounds if not evaluated carefully.

Clinical significance varies by location. A carotid bruit can indicate carotid stenosis and be associated with stroke risk; abdominal bruits may reflect visceral arterial disease or abdominal aortic aneurysm. Because auscultation alone is not definitive, imaging modalities such as duplex ultrasonography, CT angiography, or MR angiography are used to confirm the finding and guide management. Treatment focuses on addressing the underlying cause and cardiovascular risk factors, with interventions considered for significant, symptomatic, or high-risk stenoses. The term derives from the French word for noise, reflecting the audible sound produced by turbulent flow.