The cause of about half of all pericarditis cases (both acute and chronic) is unknown.
Viral infections are likely the most common cause of acute pericarditis, but the virus may never be found. Pericarditis often occurs after a respiratory infection. Bacterial, fungal, and other infections also can cause pericarditis.
Less often, pericarditis is caused by:
- Autoimmune disorders, such as lupus, scleroderma, and rheumatoid arthritis
- Heart attack and heart surgery
- Kidney failure, HIV/AIDS, cancer, tuberculosis, and other health problems
- Injury from accidents or radiation therapy
- Certain medicines, like phenytoin (an antiseizure medicine), warfarin and heparin (blood-thinning medicines), and procainamide (a medicine to treat abnormal heartbeats)
The causes of acute and chronic pericarditis are the same.
This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.