What Is a Heart Murmur?

A heart murmur is an extra or unusual sound heard during your heartbeat. Murmurs range from very faint to very loud and sometimes sound like a whooshing or swishing noise. Normal heartbeat sounds--"lub-DUPP" or "lub-DUB"--are the sounds of valves closing as blood moves through the heart. (Go to the section on "How the Heart Works" for more information about how the normal heart works.)

A heart murmur is not a disease; it is a sound that the doctor hears with the stethoscope. It may be normal for your child, or it could be a sign that something may be wrong. Most heart murmurs are harmless. Some are a sign of a heart problem, especially if other signs or symptoms of a heart problem are present.

Types of Murmurs

Innocent (harmless) murmurs. A person with an innocent murmur has a normal heart and usually has no other symptoms or signs of a heart problem. Innocent murmurs are common in healthy children.

Abnormal murmurs. A person with an abnormal murmur usually has other signs or symptoms of a heart problem. Most abnormal murmurs in children are due to congenital heart disease--heart defects present at birth. In adults, abnormal murmurs are most often due to heart valve problems caused by infection, disease, or aging.