Children's Health and Wellness

Heart Murmurs in Children

What are heart murmurs?

Heart murmurs are extra or unusual sounds made by blood moving through the heart. Murmurs are graded on a scale of 1 to 6, with 1 being very faint and 6 being very loud.

Types of murmurs include:

  • Systolic murmur. A heart murmur that occurs when the heart contracts.
  • Diastolic murmur. A heart murmur that occurs when the heart relaxes.
  • Continuous murmur. A heart murmur that occurs when the heart contracts and relaxes.

What causes heart murmurs?

Heart murmurs are common in normal, healthy children. These may be called innocent murmurs. Or a child may be born with a heart defect that causes a murmur. Other causes include:

  • Infection
  • Fever
  • Low red blood cell count (anemia)
  • Overactive thyroid gland (hyperthyroidism)

What are the symptoms of heart murmurs?

Children with innocent murmurs have no other symptoms except the abnormal heart sounds. A child with a heart murmur caused by a heart problem may have the following symptoms. They vary depending on the problem.

  • Poor feeding or eating
  • Shortness of breath
  • Sweating
  • Chest pain
  • Dizziness or fainting (syncope)
  • Bluish skin, especially of the lips and fingertips
  • Cough
  • Swelling (edema) of the lower legs, ankles, feet, belly (abdomen), liver, or neck veins

The symptoms of heart murmur can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.

How are heart murmurs diagnosed?

The healthcare provider will ask about your child’s symptoms and health history. He or she will give your child a physical exam. During an exam, the provider will listen to your child's heart with a stethoscope. If the provider hears an abnormal sound, he or she may refer you to a pediatric cardiologist. This is a doctor with special training to treat children with heart problems. Tests include:

  • Chest X-ray. An X-ray of the heart and lungs.
  • Electrocardiogram (ECG). A simple test of the electrical activity of the heart.    
  • Echocardiography (echo). An exam that uses sound waves (ultrasound) to look at the structure and function of the heart. This is the most important test to find heart murmurs.

How are heart murmurs treated?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

Many heart murmurs are normal, extra sounds in children with strong, healthy hearts. These children don’t need treatment. Some of these heart murmurs may go away on their own.

If the murmur is from a congenital heart defect, treatment may include medicine, procedures, or surgery. If the murmur is from another condition, the heart murmur will usually lessen or go away once the condition is treated.  

What are the complications of heart murmurs?

A heart murmur has no complications. But your child may have complications related to the condition causing the heart murmur. A child with a congenital heart defect may have poor growth and development, heart failure, or other serious problems.

When should I call my child's healthcare provider?

Call your child's healthcare provider if your child has any symptoms of heart disease such as:

  • Trouble feeding or eating
  • Trouble breathing

Key points about heart murmurs

  • Heart murmurs are extra or unusual sounds made by blood moving through the heart.
  • Many heart murmurs are harmless.
  • Some heart murmurs are caused by congenital heart defects or other conditions.
  • The healthcare provider hears a heart murmur when listening to your child's chest with a stethoscope.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:
  • Before your visit, write down questions you want answered.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you for your child.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.
Print Source: Up To Date. Auscultation of Cardiac Murmurs
Online Source: Centers for Disease Control and Prevention. Facts About Atrial Septal Defect
Online Source: American Heart Association. Heart Murmurs
Online Source: National Heart Lung and Blood Institute. What is a Heart Murmur?
Online Source: National Heart, Lung, and Blood Institute. What Causes Heart Murmurs?
Online Source: National Heart Lung and Blood Institute. How is a Heart Murmur Treated?
Online Editor: Metzger, Geri K.
Online Medical Reviewer: Bass, Pat F. III, MD, MPH
Online Medical Reviewer: MMI board-certified, academically affiliated clinician
Date Last Reviewed: 2/27/2015
© 2000-2015 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.