What is a heart murmur?
A heart murmur is an extra sound that the
blood makes as it flows through the heart. Your doctor uses a stethoscope to
listen to your heartbeat. When you have a heart murmur, your doctor can hear an
extra whooshing or swishing noise along with your heartbeat.
can be scary to learn that you or your child has a heart murmur. But heart
murmurs are very common, especially in children, and are usually harmless.
These normal murmurs are called "innocent" heart murmurs. There is nothing
wrong with your heart when you have an innocent murmur. Up to half of all
children have innocent murmurs.1 They usually go away
as children grow.
Adults can have innocent murmurs too. Innocent murmurs are often found in adults over 50 years of age. Murmurs also
happen when your blood flows harder and faster than usual—during pregnancy, for
example, or a temporary illness, such as a fever.1
Sometimes, though, a heart murmur is a sign of a
heart problem. This is called an abnormal heart murmur.
What causes an abnormal heart murmur?
murmurs are signs of a heart problem. In children, abnormal heart murmurs are
usually caused by problems they are born with, such as a heart valve that
doesn't work right or a hole in the wall between two heart chambers.
In adults, abnormal murmurs are most often caused by damaged heart
valves. Heart valves operate like one-way gates, helping blood flow in one
direction between heart chambers as well as into and out of the heart. See a
blood flow through a normal heart .
When disease or an infection
damages a heart valve, it can cause scarring and can affect how well the valve
works. The valve may not be able to close properly, so blood can leak through.
Or the valve may become too narrow or stiff to let enough blood through. When a
damaged heart valve cannot close properly, the problem is called
regurgitation. When the valve can't let enough blood
through, the problem is called
Heart valves can be damaged by
heart disease or by infections like
rheumatic fever or
endocarditis. The normal wear and tear that comes with
aging can also cause some damage.
Some heart murmurs are caused by
a thicker than normal heart. When the heart muscle grows too large, it can get
in the way of normal blood flow and cause a murmur.