The length of time a pericardial effusion can live is mainly related to its cause, the amount of effusion and the patient’s personal health condition, and cannot be generalized. Pericardial effusion is a fluid that normally exists in the human pericardial cavity and can play a role in heart lubrication. When the amount of fluid reaches a certain level, it can cause a significant decrease in cardiac output and return blood volume, resulting in clinical symptoms. A small amount of pericardial effusion usually does not affect the life expectancy of the patient, and close observation and active treatment of the primary disease are sufficient. In the case of a medium or large amount of pericardial effusion, patients with symptoms such as rapid heart rate, low blood pressure, chest tightness and shortness of breath may die within a short period of time due to pericardial tamponade if left untreated. Therefore, when patients have pericardial effusion, it is recommended to go to the cardiovascular medicine department of a regular hospital in a timely manner to clarify the cause and treat the symptoms, as well as actively treat the original disease, which can prolong life expectancy.