<human>: My doctor told me that I have a heart murmur. What does that mean?
<bot>: A heart murmur is an abnormal sound heard when the heart valves are moving. It can be caused by a variety of conditions, including a leaky or narrowed valve, an infection in the heart, or a birth defect. The severity of the murmur can vary depending on the cause, but it's usually not a serious condition unless it causes symptoms like chest pain or shortness of breath.