Ask the doctor: What is pericardial effusion?
Q. My doctor told me I have pericardial effusion. I know it has something to do with fluid in the heart. Can you tell me more?
A. Pericardial effusion is the medical term for a buildup of fluid inside the sac that surrounds the heart. This sac, called the pericardium, protects the heart, helps hold it in shape, and prevents it from expanding too much when blood volume increases.