Pericarditis is inflammation of the sac that surrounds and protects the heart (pericardium). Pericarditis can cause an abnormal buildup of fluid between the pericardium and the heart (pericardial effusion).

Pericarditis often improves without causing any damage to the heart. But if pericarditis causes excess fluid to build up quickly, pressure on the heart increases (cardiac tamponade), and the heart may fail.

The most common cause of pericarditis is infection with a virus. Other causes include bacterial infection, heart attack, or chest injury.

Symptoms of pericarditis include:

• Severe, sudden pain in the center or the left side of the chest that may spread to the neck, back, shoulders, or arms. Breathing deeply, moving, or lying down often makes the pain worse. Sitting up and leaning forward may relieve the pain.
• Mild fever.
• A general feeling of weakness or fatigue.

Treatment for pericarditis may include medicines to reduce inflammation and relieve pain and antibiotics if the cause is a bacterial infection. If there is any fluid buildup, it may be drained.