Acute pericarditis is a temporary inflammation of the pericardium, the double-layered membrane surrounding the heart. There are many possible causes for this condition, including virus-related infection, cancer, tuberculosis, or even as a result of myocardial infarction. The inflammation can also be associated with fluid appearing in the space between the two layers of the pericardium. Principal symptoms are fever and sudden, extremely severe chest pain, which is usually relieved when the patient leans forward, but increased by breathing and coughing. There are various tests available to investigate the cause, such as electrocardiogram and blood analysis, with diagnosis confirmed by cardiac ultrasonography. Most cases of acute pericarditis heal successfully with well-adapted treatment, but the condition can sometimes progress to cardiac tamponade, which obstructs the heart's ability to contract.