Heart Murmur Explained

What Is a Heart Murmur and What Does Heart Murmur Mean?

Heart Valves and Chambers
The Human Heart. Image © A.D.A.M.

What Is a Heart Murmur?

A heart murmur is an abnormal sound heard during auscultation, the process of listening to the heart through a stethoscope. The murmur may be an extra sound that is not typically present, louder than normal or even a longer or louder sound than is typically present.  

The ability to detect subtle murmurs comes with years of listening to heart sounds, as some murmurs are very difficult to hear and even harder to diagnose.

 Your cardiologist, or heart doctor, will be especially talented in the diagnosis of heart murmurs by listening. 

Heart sounds can change throughout the lifespan.  A murmur that is present in childhood may resolve as the child grows into an adult.  An adult may develop a murmur as they age, which may be a sign of a problem with the heart.  Procedures performed on the heart, such as a valve replacement surgery, can create new heart sounds that were not present before. 

Innocent Heart Murmur

It is important to remember that the presence of a heart murmur does not mean there is a problem with the heart, many children and adults have a heart murmur and their heart is completely healthy. In fact, the vast majority of murmurs do not indicate a serious problem.

A heart murmur that is present in a normal and healthy heart is called an innocent murmur. These are common in infants and children, and may be present during one checkup and gone during a later one.

Children can outgrow murmurs completely, or the sounds may become less pronounced over time.

Innocent murmurs may also be present in adults, and are equally harmless. Only a skilled practitioner, or medical testing such as an echocardiogram, can determine if a murmur is innocent or not.

Abnormal Heart Murmur

The other type of heart murmur, an abnormal murmur, does indicate a problem with the heart.

There may be an issue with the function of the heart itself, the structure of the heart, or the sound may be due to a malfunction of the heart valves. Murmurs can be caused by heart problems that range from mild and requiring little or no medical intervention to life-threatening, requiring immediate surgery.

In children, an abnormal murmur may be the result of a congenital heart defect. In adults, an abnormal murmur also indicates a problem, but it could be a problem that was not diagnosed in childhood or a problem that didn’t exist until adulthood. In older people, the murmur is most commonly caused by a problem with a heart valve, such as prolapse, stenosis or endocarditis.

If an abnormal murmur is suspected, an echocardiogram may be recommended to determine the nature of the problem. An EKG (electrocardiogram) may be performed, along with any additional tests that the physician deems necessary. These tests may be blood tests, or they may be other common cardiac tests such as an echocardiogram, an ultrasound of the heart.

 Another test that allows doctors to look inside the heart is a heart catheterization, a procedure where instruments are threaded through a blood vessel and up into the heart.  If the problem is severe, heart surgery may be recommended.  

The type of treatment prescribed or performed will be based on the nature of the heart problem.  The human heart has many moving parts, including chambers and valves and blood vessels, and treatment can be complicated.  Only your cardiologist (heart doctor) or cardiothoracic surgeon (heart surgeon) can give you complete information about the best treatment for your condition, the risks of treatment and the potential benefits.  It is also important to remember that many people have heart murmurs and live long and healthy lives with no need for treatment at all. 

More Information About The Human Heart & Heart Surgery


Heart Murmurs. National Heart Lung and Blood Institute. Accessed March 2009. http://www.nhlbi.nih.gov/health/dci/Diseases/heartmurmur/hmurmur_what.html

Heart Murmurs. Texas Heart Institute at St. Luke’s Episcopal Hospital. Accessed March 2009. http://www.texasheartinstitute.org/hic/topics/cond/murmur.cfm

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