Pericarditis refers to a group of diseases mainly characterized by inflammation and effusion of the pericardium. The severity of pericarditis depends on the condition of the disease. Firstly, if the inflammation and effusion of the pericardium are not severe, patients often experience symptoms such as chest tightness or chest pain. In general, this type of pericarditis is not considered severe. Secondly, if the inflammation and effusion of the pericardium are more pronounced, it can lead to pericardial effusion, especially in cases of large amounts of pericardial fluid. At this time, the condition is often quite serious, and it is essential to undergo formal treatment under the guidance of a doctor, including pericardial drainage therapy.