Version July 2025
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What is a heart murmur? —
This is an extra sound doctors or nurses hear when they listen to the heart with a stethoscope. A heart murmur usually sounds like an extra "whoosh" or "swish" in the heartbeat.
Normal heart sounds are made as the heart valves close and blood flows through the heart (figure 1). The heart valves are structures that keep blood flowing in only 1 direction. They work like swinging doors that open only 1 way. They let blood out, but not back in.
A heart murmur happens when the sound of blood flowing through the heart or blood vessels is loud enough to be heard. This can happen when the heart is working normally. It can also happen when there is a heart condition that changes the way blood flows through the heart valves, other heart structures, or blood vessels.
How do I know if I have a heart murmur? —
Most people find out they have a heart murmur during a routine exam. If your doctor or nurse hears a heart murmur, they might have you hold your breath or change your position while they listen to your heart. This tells them more about the murmur.
If I have a heart murmur, do I have a heart problem? —
Not always. People with normal hearts and blood vessels can have heart murmurs. These are called "innocent" heart murmurs. They are not caused by a heart problem.
People of any age can have an innocent heart murmur. They are especially easy to hear in people who are young, thin, or pregnant.
Other heart murmurs are abnormal. These are caused by a heart condition. Common causes of abnormal heart murmurs are:
●Problems with the heart valves – The heart valves can leak too much and let blood flow backward. Or they can get stuck and not open well.
●Other heart problems, such as a hole in one of the walls inside the heart
Will I need tests? —
Maybe. When your doctor or nurse first hears a heart murmur, they will want to know if it is innocent or abnormal. They will ask you questions and do an exam.
If your heart murmur is innocent, you do not need any tests.
If your doctor or nurse thinks your heart murmur might be abnormal or isn't sure, they might order a test to find out what is causing the murmur. The test most commonly used is an echocardiogram (also called an "echo"). This uses sound waves to create pictures of your heart as it beats. It shows the size of your heart chambers, how well your heart is pumping, and how well your heart valves are working (figure 2).
How is an abnormal heart murmur treated? —
Treatment depends on the heart condition that is causing the abnormal murmur. It also depends on how serious the condition is. If your heart condition is not serious, you might not need any treatment. But your doctor will follow your condition to see if it changes or gets worse.
If your heart condition is serious, you might need treatment. Treatment might involve surgery or a procedure that uses a thin tube called a "catheter" to reach the heart.
Do I need to take antibiotics before I go to the dentist? —
Ask your doctor. In the past, doctors recommended many people with a heart murmur take antibiotics before having certain dental or medical procedures. But now, only people with certain heart conditions need to take them. Ask your doctor if you need them for those times.
Patient education: Echocardiogram (The Basics)
Patient education: Mitral regurgitation (The Basics)
Patient education: Mitral stenosis in adults (The Basics)
Patient education: Mitral valve prolapse (The Basics)
Patient education: Aortic regurgitation in adults (The Basics)
Patient education: Aortic stenosis (The Basics)
Patient education: Tricuspid regurgitation (The Basics)
Patient education: Tricuspid stenosis (The Basics)
Patient education: Vagal maneuvers (The Basics)
