Is a Heart Murmur Dangerous?

You've likely noticed when you go in for your routine medical exam, your doctor always uses their stethoscope and listens to your heartbeat. Usually, everything is normal. However, they might hear an abnormal rhythm called a heart murmur.

While it may not have any significant impacts on your health, a heart murmur is always something to look out for.

Understanding the Sound of Blood

Oscar Gonzalez, MD, FACC, with EvergreenHealth Heart Care, says detecting a heart murmur involves the "sound of blood."

"If you think about your heart, it's a very simple pump. Its purpose is to push blood throughout your body after it collects oxygen and nutrients and then transfers those important products to all of the vital organs. The inside of the heart and all of the arteries are typically smooth, and so blood has a particular characteristic when you listen to it," he says. "Usually, it's quiet. In some people who are thin or have a very vigorous heartbeat, you'll be able to hear the natural flow of blood, but typically it's quiet. When you describe a murmur, you're describing the sound of blood, and that can vary depending on how it sounds, the direction it is going, the characteristics of the sound, quality, intensity, and so forth." All of these data points are critical in the heart examination of a murmur.

Causes of a Heart Murmur

Heart murmurs may be benign and sometimes just indicate rigorous blood flow. You may be nervous, which causes the heart to beat more vigorously, or your thyroid levels may be higher, elevating your heart rate. You may have anemia or have early sign of illness or dehydration, which all can elevate your heart rate and intensity a natural flow murmur.

"If the murmur has a particular sound, especially during a specific timing of the heart pump cycle or a specific direction in your chest, that may be a cause for concern and the provider may consider further investigation. Sometimes a referral for more diagnostic tools or studies is recommended, or perhaps a consultation with a cardiologist like myself, " says Dr. Gonzalez.

Age also becomes an important factor. A heart murmur in someone who is under 18 years old requires a different course of action compared to someone who is over 50 years old.

Diagnosing a Heart Murmur

Many heart murmurs are discovered by accident—as is the case with several heart conditions. They are often silent until they become a problem. However, your physician will know to listen for a murmur based on health history and other signs. Some heart murmurs exist without symptoms. Other cases exhibit very subtle symptoms, such as shortness of breath.

"When you get shortness of breath and the examiner listens to your heart and there is a murmur, that may raise concern. Then perhaps that murmur is causing your shortness of breath. Murmurs can be from heart valves that are either leaking or narrowing, and they may need to be surgically repaired," explains Dr. Gonzalez.

A diagnostic examination called an echocardiogram allows cardiologists to visualize where the murmur is coming from and then plan for next steps. Most likely, you and your physician will need to continue monitoring the murmur to make sure it doesn't get worse.