What are Heart Murmurs in Children?

What are Heart Murmurs in Children?

Heart murmurs are extra sounds beyond the “lub-dub” of a typical heartbeat. These extra sounds are generally caused by blood being pumped through the heart valves, chambers, and arteries

Heart murmurs in children are very common. Your pediatrician may detect a whooshing or swishing noise in addition to the regular heartbeat. Heart murmurs in most children are usually not a cause for concern, but in some cases, they could be a sign of a heart issue that may require treatment.

Types of Heart Murmurs in Children

Types of Heart Murmurs in Children

Heart murmurs are common in infants and children. In fact, the majority of children have innocent murmurs during infancy and/or childhood. But there are types of abnormal heart murmurs that may indicate a heart defect.

There are two general categories of heart murmurs:

  • Innocent murmurs. Also called “functional murmurs,” innocent murmurs are the most common in children. They are harmless and do not require treatment, surgery, or lifestyle restrictions. Innocent heart murmurs often come and go, and most eventually go away as a child gets older. They are often louder when children are febrile and being seen for sick visits by their pediatrician.
  • Pathological murmurs. Pathological murmurs are rare and found in a small minority of children with heart murmurs. They are typically louder than innocent murmurs, may produce a “clicking” sound heard through a stethoscope, and may radiate to other parts of the body such as the back. These murmurs can be connected to a congenital heart defect, disease, or infection.

Types of child heart murmurs can be further categorized into the following

  • Systolic murmur, the heart murmur that occurs when the heart muscle constricts (tightens)
  • Diastolic murmur, which occurs when the child’s heart relaxes
  • Continuous murmur, which is continuous throughout the cardiac cycle, occurring during the contraction and relaxation of the heart muscle

Evaluating Childhood Heart Murmurs

Evaluating Childhood Heart Murmurs

Types of heart murmurs can be evaluated by loudness, pitch, duration, and intensity. They may produce a “thrill”—a noticeable vibration that can be felt with the palm of the hand on the heart.

Your pediatrician may evaluate a heart murmur by listening carefully with a stethoscope for how loud the murmur is, what the pitch of the murmur is, where on the chest it is best heard, and whether it radiates to other parts of the body. If your pediatrician thinks the murmur is innocent, it may be something they will continue to follow. It is important to let any new practitioners know that your child has an innocent murmur when they see your child for the first time.

Heart murmurs can be graded on a scale of one to six (I-VI):

  • I: Barely audible
  • II: Faint, but audible
  • III: Loud, without a palpable thrill
  • IV: Loud, with a palpable thrill
  • V: Very loud murmur, heard with a stethoscope placed lightly on the chest
  • VI: Very loud murmur that can be heard without a stethoscope

Signs & Symptoms of Childhood Heart Murmur


Children with innocent heart murmurs generally have no additional symptoms beyond irregular heart sounds. However, depending on the underlying cause, pathological heart murmurs may be associated with a cardiac issue that produces the following symptoms:

  • Shortness of breath or rapid breathing
  • Poor appetite
  • Weight gain
  • Chest pain
  • Sweating
  • Dizziness or fainting
  • Cough
  • Swelling (edema) in the belly, lower legs, ankles, feet, liver, or neck veins
  • Bluish skin, particularly on the fingertips and lips

If your child is experiencing any of these symptoms, consult your pediatrician for a diagnosis and treatment options. If your pediatrician is concerned the murmur is not innocent, they may refer you to see a pediatric cardiologist.

What Causes a Heart Murmur in Children?


In most cases of innocent heart murmurs, there is usually no underlying cause. A heart defect or other medical conditions may cause pathological heart murmurs.

Causes of pathological heart murmurs can include:

Risk Factors

Risk Factors

Any child can be born with a heart murmur. However, there are certain factors that can increase the risk of developing a pathological heart murmur, including:

  • Weakened heart muscle (cardiomyopathy)
  • Infection of the heart lining (endocarditis)
  • Autoimmune disorders, such as lupus and rheumatoid arthritis
  • A history of rheumatic fever
  • Uncontrolled diabetes in the mother while pregnant
  • German measles (rubella) in the mother while pregnant
  • Use of alcohol, drugs, and certain medications by the mother during pregnancy
  • Family history of heart issues linked to heart murmurs such as congenital heart disease
Get Care

Trust NewYork-Presbyterian for Childhood Heart Murmur Care

NewYork-Presbyterian is one of the leading hospitals in the nation for pediatric cardiology. If you have concerns about your child’s symptoms of heart murmur, our caring team of pediatricians and pediatric cardiologists can help determine if further tests and treatments are required, and provide access to some of the best specialists in heart care.

For help with your child’s heart murmur, or any other childhood heart conditions, contact NewYork-Presbyterian for a consult with one of our pediatricians or cardiac specialists.