Dr. Kerry Rosen is Director of Outpatient Services at Nationwide Children's.

Q: I recently took my 4-year-old daughter to her yearly check-up. The doctor said that he thought he heard a heart murmur while listening to my daughter's heart and recommended we get a second opinion from a cardiologist. Though the doctor said it may be nothing to worry about, I am concerned - what could this be, and what could be causing it?

A: A murmur is simply a sound or noise that a nurse, doctor or advanced practice provider (nurse practitioner or physician assistant) hears during a checkup or physical examination. In a normal heart, they are made by blood circulating through the normal heart.

Not all heart murmurs are symptoms of heart disease. Normal murmurs are referred to as innocent, functional or benign murmurs. In fact, approximately 50 percent of all children with normal hearts can occasionally experience an innocent heart murmur. These innocent murmurs are not related to congenital heart defects, and often resolve by the time a child reaches adulthood. Also, innocent murmurs are often easier to hear if your child has a fever or other illness.

Someheart murmurs, however, are caused by heart problems such as abnormal holes or valve abnormalities.

If your primary care provider wants the murmur evaluated further, referral to a cardiologist can help sort out if the sound is normal or needs more testing or work up. The cardiologist will evaluate a murmur based on several factors such as the pitch, loudness and duration of the murmur. They are also graded according to their intensity.

If your primary care provider or cardiologist diagnoses an innocent murmur, special precautions are not needed.

-Dr. Kerry Rosen is Director of Outpatient Services at The Heart Center at Nationwide Children's Hospital and an Associate Professor of Clinical Pediatrics at The Ohio State University College of Medicine.