Q: Is an enlarged heart a health danger in someone who doesn't have blood clots or other heart disease?

A: It can be a danger, but it isn't always. Large people have large hearts, and athletes often have enlarged hearts to handle the bigger workload their hearts must handle. In these cases, a larger-than-normal heart isn't a sign of trouble.

However, hearts can also be enlarged because of serious conditions. Sometimes, the heart enlarges because a disease, heart attack or virus weakens it. In other cases, the heart enlarges because it has to pump so much more blood due to problems like leaking heart valves.

Most people learn they have an enlarged heart when they have an electrocardiogram or echocardiogram. In people with serious problems behind their enlarged hearts, these tests usually reveal evidence of the cause of the problem.

Your doctor can usually figure out whether your enlarged heart is serious by considering "the company it keeps." This means how you look and feel and whether you have signs of a serious disease that can cause enlargement. If you feel fine and can exercise vigorously, and you happen to undergo a test that shows an enlarged heart, there may not be anything to worry about.