Pericarditis causes chest pain that is especially acute beneath the ribcage and sternum. This pain may also be felt occur in the shoulder, neck and upper back. It is often aggravated by breathing, during which the movement of the heart and lungs in the chest cavity may irritate the pericardium. Changes in body position may increase or decrease the intensity of the discomfort. Pericarditis may be detected from an electrocardiogram (ECG).

Normally, pericarditis is not life-threatening, though it may lead to a pericardial effusion in which fluid accumulates between the pericardium and the heart muscle. If large, this may cause difficulty in breathing (dyspnea) and exert pressure on the heart chambers, making the heart work harder to pump blood to the lungs and body tissues. An echocardiogram is usually performed in patients suspected of pericarditis and will demonstrate the presence of increased fluid in the pericardial space (a pericardial effusion).