A bruit (pronounced “broo-ee”) is an abnormal sound heard during a medical examination, typically indicating turbulent blood flow within an artery. This sound is distinct from normal heart sounds and serves as a clinical sign that often prompts further investigation. While some bruits can be harmless, others may signal underlying health issues.
Understanding the Sound
A bruit is produced when blood flows through a narrowed or irregular artery, creating a “whooshing” or “buzzing” sound. This phenomenon is similar to how water rushing through a constricted pipe generates turbulence and noise. Medical professionals detect bruits using a stethoscope, a process called auscultation, by placing the instrument over the suspected artery.
Bruits are often confused with heart murmurs, but they originate in different locations. Heart murmurs are sounds resulting from turbulent blood flow within the heart, typically due to issues with heart valves. In contrast, bruits are heard over arteries outside the heart, reflecting turbulent flow in the peripheral vascular system. Their distinct locations help doctors differentiate their causes.
Common Locations and Underlying Causes
Bruits can be detected in various arteries throughout the body, with specific locations often pointing to particular underlying conditions. One common site is the carotid arteries in the neck, which supply blood to the brain. A carotid bruit typically suggests carotid artery stenosis, a narrowing of these arteries often caused by atherosclerosis, a buildup of fatty plaque on artery walls. This narrowing can increase the risk of stroke.
Abdominal bruits may indicate issues within the abdominal aorta or its branches. A midline systolic bruit in the upper abdomen, especially if accompanied by a pulsatile mass, can suggest an abdominal aortic aneurysm (AAA), a weakened and bulging area in the aorta. Bruits heard over the flanks or sides of the abdomen can point to renal artery stenosis, a narrowing of the arteries supplying the kidneys, which is often linked to high blood pressure.
Bruits can also be found in the femoral arteries located in the groin, which supply blood to the legs. A femoral bruit often indicates peripheral artery disease (PAD), a condition where plaque buildup narrows arteries in the limbs. These bruits suggest reduced blood flow to the lower extremities.
How Bruits Are Evaluated and What They Indicate
The detection of a bruit during a physical examination is a clinical sign that requires further investigation. Initial evaluation often involves careful auscultation by a healthcare provider, noting the location, timing, and characteristics of the sound. However, auscultation alone cannot confirm the exact cause or severity of the underlying condition.
To identify the specific pathology, doctors often order diagnostic tests. Doppler ultrasound is a common first-line imaging study, particularly for carotid, renal, and peripheral arteries, as it provides detailed information about blood flow and the degree of narrowing. Other advanced imaging techniques, such as CT angiography (CTA) or magnetic resonance angiography (MRA), may be used for a more comprehensive view of the arteries, especially for aneurysms or complex vascular issues.
Not all bruits indicate a serious health problem. For instance, some bruits, particularly in children, are considered “innocent” or benign, due to normal blood flow. However, in adults, bruits often signal underlying arterial disease like atherosclerosis, which can increase the risk of conditions such as stroke or heart attack. Therefore, any detected bruit requires medical evaluation to assess its cause and determine appropriate management.