What are heart murmurs in children?

Heart murmurs are extra or abnormal sounds made by turbulent blood flowing through the heart. Murmurs are graded on a scale of 1 to 6, based on how loud they are. One means a very faint murmur. Six means a murmur that's 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 throughout. the heartbeat.

What causes heart murmurs in a child?

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

• Infection

• Fever

• Low red blood cell count (anemia)

• Overactive thyroid gland (hyperthyroidism)

• Heart valve disease

What are the symptoms of heart murmurs in a child?

Children with innocent murmurs have no other symptoms except the abnormal heart sounds. A child with a pathologic heart murmur may have 1 or more of the following symptoms. They vary depending on the problem.

• Poor feeding, eating, or weight gain

• Shortness of breath or breathing fast

• 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. Have your child see their healthcare provider for a diagnosis.

How are heart murmurs diagnosed in a child?

The healthcare provider will ask about your child’s symptoms and health history. They will do a physical exam on your child. During an exam, the provider will listen to your child's heart with a stethoscope. If the provider hears an abnormal sound, they 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 creates images of the heart and lungs.

• Electrocardiogram (ECG). This test measures the electrical activity of the heart.

• Echocardiography (echo). This exam 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 in a child?

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 with time.

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 possible complications of heart murmurs in a child?

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.

Call 911

Call 911 if any of the following occur:

• Chest pain

• Rapid or irregular breathing or blue lips

• Passing out or unresponsiveness

Key points about heart murmurs in children

• Heart murmurs are extra or unusual sounds made by turbulent blood flowing through the heart.

• Many heart murmurs are harmless (innocent).

• Some heart murmurs are caused by congenital heart defects or other conditions. These are called pathologic.

• If the healthcare provider hears a heart murmur when listening to your child's chest with a stethoscope, they may refer you to a pediatric cardiologist for more tests.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• 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 healthcare provider after office hours. This is important if your child becomes ill and you have questions or need advice.