Definition

A heart murmur is an abnormal extra sound made when the heart beats. The sound is produced by blood moving through the heart and its valves.

Description

Blood flows from the body into the heart through veins. It moves from one side of the heart (the atria) into the other side of the heart (the ventricles). It then flows out of the heart through arteries. The flow of blood is controlled by muscular flaps called valves. The valves open and close as blood flows through each part of the heart. When the valves between the atria and the ventricles close, they make a "lubb" sound. When the valves between the ventricles and the major arteries close, they make a "dubb" sound. When doctors listen to the heart beat of a healthy person, they hear a "lubb-dubb" sound.

A heart murmur is a sound other than...