What is a heart murmur?

A heart murmur is an unusual sound heard during a heartbeat. It happens when blood flows through the heart in a way that creates extra noise. Some murmurs are harmless, while others may signal a heart condition that needs attention.

Common causes vary depending on the type of murmur:

• Harmless (innocent) murmurs may occur during:
  • Fever or illness
  • Pregnancy
  • Physical activity
  • Anemia or thyroid conditions
  • Growth spurts in children
• Abnormal murmurs may be linked to:
  • Heart valve problems (narrowing or leaking)
  • Structural heart differences present at birth
  • Thickened heart muscle

Symptoms

Most heart murmurs don’t cause symptoms and are often found during a routine exam. When symptoms do occur, they are usually related to an underlying heart issue.

Possible symptoms include:

• Feeling tired or weak
• Shortness of breath, especially with activity
• Chest discomfort
• A racing or irregular heartbeat
• Swelling in the legs, feet, or abdomen
• Lightheadedness or fainting

How is it diagnosed?

Your provider will begin by listening to your heart with a stethoscope. If a murmur is detected, additional tests may be recommended to understand the cause.

These may include:

• An echocardiogram to view how the heart and valves are working
• An electrocardiogram (ECG) to check heart rhythm
• A chest X-ray to look at heart size and lungs
• In some cases, more detailed imaging or procedures

These tests help determine whether the murmur is harmless or related to a heart condition.

How is it treated?

Treatment depends on the cause of the murmur.

• Many people with innocent murmurs don’t need treatment
• If a medical condition is causing the murmur, treating that condition may resolve it
• Medications may be used to manage symptoms or support heart function
• In more serious cases, procedures or surgery may be needed to repair or replace a heart valve or correct a structural issue

Some murmurs improve over time, while others require ongoing monitoring and care.