What is a murmur?
A murmur is a sound your doctor hears when listening to the heart with a stethoscope. Murmurs are caused by the sound of blood moving through the heart. Some murmurs are due to structural abnormalities of the heart, such as a hole in the heart or a valve abnormality. But, most murmurs are normal and not due to any heart problem. These normal murmurs are called innocent, functional, or benign murmurs. Innocent murmurs are very common in children. Your cardiologist can determine whether your child’s murmur is innocent by listening to your child’s heart with a stethoscope. Sometimes, an echocardiogram (an ultrasound of the heart) is needed to determine whether any structural abnormalities are present.
When people hear the “lub-dub” that they think is the heart beating, they are really listening to the sounds of the valves in the heart closing. The heartbeat itself — the contraction of the heart muscle to pump out the blood — is silent. Most of the time, blood flowing through the heart is also silent. When the turbulence of blood flowing through the heart can be heard, the person is said to have a murmur (like the murmuring of a babbling brook). Some murmurs indicate an abnormality in the structure of the valves or walls of the heart, or of the major blood vessels. These problems can be insignificant or can be quite severe. Other murmurs can arise from normal hearts, and represent no problem whatsoever. Skilled physicians can reliably distinguish between the different types of murmurs using a very low-tech instrument — the stethoscope. By simply listening, one can learn to recognize the different classes of murmurs by their intensities, their timing, their locations, and the chara
