Pericarditis is swelling and irritation of the pericardium, the thin sac-like membrane surrounding your heart. Pericarditis often causes chest pain and sometimes other symptoms. The sharp chest pain associated with pericarditis occurs when the irritated layers of the pericardium rub against each other.
Pericarditis usually begins suddenly but doesn't last long (acute). When symptoms develop more gradually or persist, pericarditis is considered chronic.
Most cases are mild and usually improve on their own. Treatment for more-severe cases may include medications and, rarely, surgery. Early diagnosis and treatment may help to reduce the risk of long-term complications from pericarditis.