What is a heart murmur in a child?

A heart murmur is a sound made by the flow of blood through the heart when a doctor listens with a stethoscope.

Many children have heart murmurs, which can vary as a child grows. If we were to listen to a child’s heart throughout their lifetime, we likely would hear a murmur in most children.

Since only about 1 percent of children have congenital heart disease, this means 99 percent of the extra sounds, or murmurs, doctors hear are normal. We call these innocent or benign murmurs, and they are caused by blood flow through a normal heart.

Often, it’s easier to hear soft murmurs because children have thin chest walls and the heart is closer to the stethoscope. Sometimes the heart is beating faster, increasing the turbulence of blood flow. These factors allow a doctor to hear the blood flow through a structurally normal heart.

Norton Children’s Heart Institute

Each heart murmur is investigated and a custom care plan is developed for each child. To schedule an appointment, call

When does a child’s heart murmur need further evaluation?

If pediatric heart murmurs are common, why would your doctor suggest more testing for your child? Your pediatrician may refer heart murmurs in kids to a cardiologist based on several things, including:

  • If the heart murmur is very loud.
  • How the heart murmur changes with your child’s position (i.e. lying, sitting, standing).
  • When the murmur is heard in relationship to other normal heart sounds.
  • Related symptoms such as shortness of breath, not feeding well, or poor growth (younger children).
  • Related symptoms such as palpitations, fainting, or chest pain, particularly if these symptoms occur with physical activity (older children).
  • Family history of inherited heart conditions .

Ashley E. Neal, M.D., is assistant professor of pediatrics and co-director of medical education, Division of Pediatric Cardiology, University of Louisville School of Medicine. She sees patients at UofL Physicians – Pediatric Cardiology.


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