Heart Murmurs


A heart murmur is sound produced by turbulent blood flow, particularly from the heart's valves. They can be found in infants or develop later in life. A heart murmur is often innocent and doesn't require treatment.

Heart Murmur Audio

Stethoscopes are used to listen to heart murmurs. A normal heartbeat sounds like "lub-DUB", which are the sounds of your heart valves closing. This "lub-DUB" sound changes, often with additional sounds being heard.

Heart Murmur Sounds

On this website, we provide lessons, reference guides and quizzes for auscultating heart murmurs. This includes gaining an understanding of cardiac rate and rhythm, conditions of the valves and possible anatomical abnormalities such as congenital defects. Links to our lessons, guides and quizzes are found in the 'Quick Links' box to the left. The remainder for this pages provides an overall listening guide for heart murmurs.

Timing and Cadence

Systolic murmurs occur between the first heart sound (S1) and the second heart sound (S2). Diastolic murmurs occur between S2 and S1. In addition, timing is used to describe when murmurs occur within systole or diastole. For example, early systolic, midsystolic or late systolic. See our courses on Systolic and Diastolic Murmurs for more information including audio recordings, waveforms and animations.

Heart Auscultation Points

Cardiac auscultation is performed systematically over five heart auscultation points on the anterior chest wall. Please refer to the torso illustation for each point. Use the stethoscope's diaphragm, switching to the bell to hear lower pitched sounds.

heart murmurs location areas
aortic valve auscultation location area Aortic Valve Area Second right intercostal space (ICS), right sternal border
pulmonic valve auscultation location area Pulmonic Valve Area Second left intercostal space (ICS), left sternal border
Erb's Point  auscultation location area Erb's Point Third left ICS, left sternal border
tricuspid valve auscultation location area Tricuspid Valve Area Fourth left ICS, left sternal border
mitral valve auscultation location area Mitral Valve Area Fifth ICS, left mid-clavicular line


Heart murmur duration refers to the portion of systole or diastole that the murmur occupies. Terms used include short and long. Murmurs lasting throughout systole are referred to as holosystolic or pansystolic.


Evaluation of the murmur's pitch should be made by classifying the pitch (frequency) as low, medium or high. The stethoscope's bell can be helpful with low-pitched sounds while the diaphragm is used for medium or high-pitched sounds.


Some murmurs are described by the sound's shape. Common classifications include crescendo (increasing intensity), decrescendo (decreasing intensity), crescendo-decrescendo (increasing then immediate decreasing intensity). Crescendo-decrescendo is also called diamond shaped. Rectangular, also termed plateau indicates a heart murmur of constant intensity. Our lessons include waveforms that illustrate these shapes.

diamond shaped murmur decrescendo murmur

Tonal Quality

Listen for additional aspects of the murmur's sounds. Heart murmurs may have qualities that can be noted as musical, harsh, blowing, booming, sharp or dull.

Respiration and Patient Position

Respiration or patient position can influence murmur intensity as well as heart sound splitting. These factors will be described within the heart sound lessons. Generally speaking, murmurs increasing with expiration originate with left side (aortic or mitral) valves, while murmurs increasing in intensity with inspiration originate with tricuspid or pulmonary valves.

Within each lesson, the author provides an sketch of the patient's position during auscultation, such as supine, left lateral decubitus, squatting or sitting.


Here is an example of a heart murmur. In this case, the murmur is Aortic Stenosis.


patient thorax when auscultating by stethoscope

patient position during auscultation
The patient was sitting during auscultation.


A waveform of the heart sound's amplitude is called a phonocardiogram.

Heart Sounds Reference Guide

Our auscultation reference guide provides quick access to this sound as well as many other adventitious sounds. Each sound is described also with an audio recording and waveform.

Quick Links to Other Breath Sounds

While we have many breath sound lessons and quick references on this website. Please use the links below.

Authors and Reviewers


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