Pericardial disorders refer to a group of conditions that affect the pericardium, the thin, double-layered sac surrounding the heart. The pericardium serves to protect the heart and maintain its position in the chest cavity. Disorders of the pericardium can include inflammation (pericarditis), fluid accumulation (pericardial effusion), and constriction (constrictive pericarditis), each of which can impact heart function and cause various symptoms.