AuscultifyCarotid Bruit: What It Sounds Like, Causes and How to Auscultate
A carotid bruit is a soft, blowing whoosh heard over the carotid artery in the neck, timed with systole and loudest between the angle of the jaw and mid-neck. It is most often caused by atherosclerotic narrowing at the carotid bifurcation, and it is found in roughly 4 to 5 percent of adults over 45. A bruit tells you there is turbulence; it does not tell you how tight the stenosis is, and about half of significant stenoses produce no bruit at all.
How to auscultate the carotid arteries
Carotid auscultation is quick when it is done in a fixed sequence:
- Position. Patient sitting or supine with the head turned slightly away from the side you are examining, neck muscles relaxed.
- Chest piece. Use the bell for the low-pitched sounds most carotid bruits produce; the diaphragm is an acceptable alternative and picks up higher-pitched bruits well. Apply it with light pressure. Pressing hard narrows the artery and can create a bruit that is not really there.
- Three points. Listen just below the angle of the jaw (the bifurcation, where most plaques sit), at mid-neck along the medial edge of the sternocleidomastoid, and at the base of the neck just above the clavicle.
- Breath-hold. Ask the patient to take a breath in and stop breathing for a few seconds. Breath sounds transmitted through the trachea easily bury a soft bruit.
- One side at a time. Never auscultate or palpate both carotids simultaneously. Bilateral pressure can drop cerebral perfusion or trigger a vagal response in a patient with carotid sinus sensitivity.
- Check the chest. If you hear anything, move to the right upper sternal border. A sound that is louder there than in the neck is a heart murmur, not a bruit.
Finish by listening in each supraclavicular fossa for a subclavian bruit and, if there is one, measure blood pressure in both arms.
What a carotid bruit sounds like
Expect a low to medium pitched "whoosh" or "shh" that begins after the upstroke of the pulse and stops before the next beat. It is loudest in the neck and fades as you move toward the chest. A harsh, high-pitched bruit, or one that extends into diastole, suggests a tighter lesion with a persistent gradient. Very tight stenosis, above roughly 90 percent, often becomes quiet again as flow falls, and a complete occlusion is silent.
Causes and differentials
| Cause | Clues on examination |
|---|---|
| Internal carotid stenosis | Systolic bruit loudest high in the neck near the angle of the jaw; may be harsh; risk factors for atherosclerosis; may have had TIA or amaurosis fugax |
| External carotid stenosis | Sounds identical on auscultation; only imaging separates it from internal carotid disease |
| Transmitted aortic stenosis murmur | Loudest at the right upper sternal border, radiates upward into both carotids, gets softer as you move up the neck; slow-rising pulse, soft or absent A2, ejection click |
| Venous hum | Continuous, low-pitched hum at the base of the neck, usually on the right, loudest in diastole; disappears when the patient lies flat or with gentle pressure over the internal jugular; common in children |
| Hyperdynamic states | Soft bilateral systolic sounds with fever, anemia, pregnancy, thyrotoxicosis; resolve with the underlying condition |
| Thyroid bruit | Heard over the goitre itself in Graves disease, often continuous; diffuse enlarged gland, thrill, tremor, tachycardia |
| Subclavian stenosis | Bruit in the supraclavicular fossa; inter-arm blood pressure difference above 15 to 20 mmHg; possible subclavian steal symptoms |
Distinguishing a carotid bruit from aortic stenosis
This is the differential examiners care about most. Both sounds are systolic and both can be heard in the neck. Use gradient and character:
- Where is it loudest? Aortic stenosis peaks at the right upper sternal border and decreases as you go up the neck. A carotid bruit peaks in the neck and decreases as you go down toward the sternum.
- Timing and shape. Aortic stenosis is a crescendo-decrescendo ejection murmur that starts after S1 and ends before S2. A carotid bruit is usually a softer, more uniform blowing sound without a clear diamond shape.
- Company it keeps. A slow-rising, low-volume pulse, a soft A2 and a sustained apex beat point to the valve.
If you are still unsure, the honest answer is echocardiography plus carotid duplex. The cardiac auscultation areas guide covers the radiation pattern of aortic stenosis in more detail.
What a carotid bruit means
A bruit is neither sensitive nor specific for hemodynamically significant stenosis. Pooled studies put sensitivity for a 70 percent or greater stenosis at roughly half to two thirds, with specificity somewhere between about 60 and 90 percent depending on the population, so figures vary by source. Stenosis can be silent, and a bruit can come from a mild plaque or an entirely different cause.
What a bruit reliably tells you is that the patient has atherosclerosis. An asymptomatic carotid bruit is associated with roughly a doubling of stroke risk and, at least as importantly, with a higher risk of myocardial infarction and cardiovascular death. Most strokes in these patients do not even come from the carotid with the bruit; the bruit is a marker of a diseased vascular tree.
Management of an asymptomatic bruit is a clinical decision rather than a reflex. Reasonable steps are duplex ultrasound to quantify stenosis, aggressive risk factor treatment (antiplatelet, statin, blood pressure, smoking, diabetes), and vascular referral when imaging shows severe disease. Any patient with a bruit and symptoms of TIA or stroke in the same territory needs urgent imaging.
Documentation phrasing
Say where it was loudest, its timing and what you excluded. For example: "Soft systolic bruit right carotid, loudest just below the angle of the jaw, not heard at the right upper sternal border, no thrill, left carotid clear, supraclavicular fossae clear." For a suspected transmitted murmur: "Systolic ejection murmur RUSB radiating to both carotids, louder at the sternal border than in the neck."
Practice carotid bruit vs aortic stenosis
The neck-versus-chest gradient is easy to describe and hard to hear until you have compared the two side by side. Auscultify's library of real clinical recordings includes vascular and valvular sounds, and its six quiz modes make you name the sound before revealing the answer. Sounds you miss are weighted to reappear through spaced repetition, and the Spectrogram view (Pro) shows the crescendo-decrescendo shape of aortic stenosis against the flatter profile of a bruit.
Train vascular sounds free →FAQ
What does a carotid bruit sound like?
A soft, blowing whoosh over the carotid artery, timed with systole and loudest at mid-neck or near the angle of the jaw. It is low to medium pitched, fades toward the chest, and is best heard with the bell applied lightly while the patient holds their breath.
What is a carotid bruit?
A carotid bruit is the sound of turbulent flow heard over the carotid artery. It is most often caused by atherosclerotic narrowing, but it can also be a transmitted aortic stenosis murmur, a venous hum, a thyroid bruit or a flow sound from a high-output state.
Where do you listen for a carotid bruit?
At three points along the artery: just below the angle of the jaw over the bifurcation, at mid-neck along the medial border of the sternocleidomastoid, and at the base of the neck above the clavicle. Add the supraclavicular fossa for the subclavian artery.
How do you auscultate carotid arteries for bruits?
Place the bell or diaphragm lightly over the artery, ask the patient to hold their breath, and listen through several beats at each of the three sites. Examine one side at a time, never compress the vessel, and if you hear a sound, check the right upper sternal border for a transmitted murmur.
What does a carotid bruit mean?
It means turbulent flow in the neck, most often from carotid atherosclerosis. It roughly doubles stroke risk and marks generalized atherosclerosis, but it is neither sensitive nor specific for significant stenosis, so duplex ultrasound is needed to measure the narrowing.
What is a supraclavicular bruit?
A bruit heard in the hollow above the clavicle, over the subclavian artery. It suggests subclavian stenosis and should prompt a comparison of blood pressure in both arms; in young people a soft supraclavicular systolic sound is often a benign flow murmur.