Pericarditis occurs when the pericardium, the sac that surrounds your heart, becomes red, swollen and inflamed. It can affect people of all ages, but men ages 20 to 50 are more likely to develop it than others.
In many cases, the cause of pericarditis remains unknown. However, some things are known to trigger pericarditis. They include autoimmune diseases, bacterial and fungal infections, kidney failure and viruses.
Though a reaction is rare, medications such as phenytoin (an anti-seizure medicine) and procainamide (a medicine to treat irregular heartbeats) have been known to cause pericardium.