human
My doctor says I have a heart murmur, and I'm worried. What is a heart murmur?
assistant
A heart murmur is a sound made by the blood as it flows through your heart. It's caused by a problem with the valves in your heart. The valves are supposed to open and close to let blood flow through your heart, but if they don't work correctly, they can cause a leaky valve that makes a murmur.