Pericarditis (PER-ih-kar-DI-tis) is a condition in which the membrane, or sac, around your heart is inflamed. This sac is called the pericardium (per-ih-KAR-de-um).
The pericardium holds the heart in place and helps it work properly. The sac is made of two thin layers of tissue that enclose your heart. Between the two layers is a small amount of fluid. This fluid keeps the layers from rubbing against each other and causing friction.
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