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 valves closing as blood moves through the heart. (Go to the How the Heart Works section for more information about how a normal heart works.)

A heart murmur is not a disease; it is a sound that the doctor hears with a stethoscope. It may be normal, or it could be a sign that something may be wrong. Most heart murmurs are harmless. Some are signs of heart problems, 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 signs or symptoms 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 defects—heart defects present at birth. In adults, abnormal murmurs are most often due to heart valve problems caused by infection, disease, or aging.

from nhlbi.nih.gov
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