Harmless Heart Murmur vs. Abnormal Heart Murmur: Know the Difference

The unusual sounds of a heart murmur aren’t classic heart disease symptoms, but they could indicate trouble nonetheless.

heart murmur

An innocent heart murmur typically won't cause problems, but an abnormal heart murmur requires attention. Screening starts with the simple step of your physician listening to your heart.

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If you’ve ever been told you have a heart murmur, you may be inclined to immediately think you have heart disease. Symptoms of heart disease, however, usually include things like chest pain, shortness of breath, and lightheadedness as well as test results that show high cholesterol, high blood pressure, and other signs of a weak heart or poor circulation.

A heart murmur, however, is often harmless. It’s usually first detected when a physician listens to your heart with a stethoscope.

Diagnosing Heart Murmurs

A heart murmur is sometimes described as a “whooshing” noise or simply an extra sound during a heartbeat. The noise is caused by an unusual flow of blood through the heart valves and chambers.

Once a heart murmur is detected with a stethoscope exam, your doctor will listen to it carefully and grade it on a scale of 1 to 6. Other features your doctor will note include the length of the murmur, where it can be heard in the chest (or the back or neck, too), whether it has a high or low pitch, and where the murmur is heard in the heartbeat.

Once the sound is better understood, your doctor will likely refer you for one or more imaging tests, such as a chest X-ray or an echocardiogram, which uses sound waves to create a picture of the structure and function of the heart.

Harmless Heart Murmurs

Usually “innocent heart murmurs,” as they are called, are caused by a more-rapid-than-usual flow of blood through the heart. It’s common among newborns and adolescents. Physical activity can also produce an innocent heart murmur.

When a woman is pregnant, her body produces extra blood to support the baby. So it’s quite common for a heart murmur to be heard during a regular checkup.

If a heart murmur is harmless, there usually aren’t other symptoms. That’s because the murmur isn’t the result of a heart problem.

Abnormal Heart Murmur Concerns

An abnormal heart murmur could be a valvular heart disease symptom. When a heart valve becomes stiff, the condition is known as valve stenosis. The result is that the valve no longer opens properly, so blood has a harder time passing through that valve. The opposite problem can also occur. When valves can’t close completely, it’s known as valve regurgitation.

Heart murmurs are often the result of holes in the valves or chambers. A hole in any part of the heart is a septal defect. In most cases septal defects are present at birth. When you’re born with a heart problem, it’s known as a congenital heart defect.

Treatment for a congenital heart defect depends on the severity and location of the problem. In some cases, medications can help control symptoms and manage a septal defect, even if they can’t cure the condition. Medications such as beta blockers to help steady the heartbeat, and anticoagulants to help reduce the risk of stroke, are among those that are commonly prescribed.

If the hole can be treated surgically, an operation may be able to close the hole and stop the heart murmur.

Another heart murmur cause is hypertrophic cardiomyopathy. It’s a condition in which heart muscle cells enlarge and the walls of the heart thicken. This can lead to problems with the mitral valve, which in turn, can result in a heart murmur. If the valve disease becomes too serious, a valve repair or replacement procedure may be needed.

The Importance of Screening

It’s important to remember that an abnormal heart murmur isn’t a condition in and of itself. Rather, it’s one of many heart disease symptoms that indicates an underlying problem.

It may be an innocent heart murmur, but until there’s a thorough evaluation, you and your doctor won’t know. If you get a heart murmur diagnosis, and your doctor doesn’t take it seriously or pursue any follow-up screenings, ask why. Make your concerns known. And if you still aren’t satisfied, seek a second opinion.

Hopefully, a heart murmur heard during your routine exam is harmless. But it might not be. So get proper diagnosis and explore your options thoroughly.


Originally published in 2016 and regularly updated.


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Jay Roland

Jay Roland has been executive editor of Massachusetts General Hospital’s Mind, Mood & Memory since 2017. Previously, he held the same position with Cleveland Clinic’s Heart Advisor, since 2007. In … Read More

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