what is the pericarditis
Pericarditis is swelling and irritation of the pericardium, which is the sac that surrounds your heart. Pericarditis usually doesn't cause serious problems. Most people get better in 7 to 10 days. When there are problems, they may include: 1  A buildup of fluid in the pericardial sac (pericardial effusion). 2  Sudden pressure on the heart and sudden difficulty pumping enough blood (called cardiac tamponade). 3  Constrictive pericarditis, which can occur when pericarditis comes back or becomes a longer-term problem.