Pericarditis refers to the inflammatory disease of the visceral and parietal layers of the pericardium. It can be classified according to its etiology into infectious, non-infectious, allergic, and immune pericarditis. Causes of infectious pericarditis include viral, purulent, tuberculous, and fungal pericarditis. Non-infectious pericarditis can be caused by acute myocardial infarction, uremia, tumors, trauma, aortic dissection, radiation, acute idiopathic, and sarcoidosis, among others. Causes of allergic or immune pericarditis include rheumatic, vasculitis, drugs, and more. Some patients remain undiagnosed after examinations and are categorized as having idiopathic pericarditis or nonspecific pericarditis.