Increased amounts of fluid within the sac surrounding the heart, usually due to inflammation.
Pericardial Effusion is an abnormal collection of fluid inside the sac that covers the heart. With pericarditis, the amount of fluid increases within the pericardial layers, squeezes the heart, and can restrict the motion of the heart, called a pericardial effusion.
Pericarditis is usually a complication of viral infections, most commonly echovirus or coxsackie virus, and less frequently, caused by influenza or HIV infection.
Infections with bacteria can lead to bacterial pericarditis (also called purulent pericarditis). Some fungal infections can also produce pericarditis.