Whether pericardial effusion is prone to recurrence depends on the causes of the effusion. There are many causes of pericardial effusion, such as organic heart disease, heart failure, tumors, tuberculosis, and hypoproteinemia, all of which can lead to the development of pericardial effusion. Among these, pericardial effusion caused by tuberculous pericarditis will not recur as long as standardized anti-tuberculosis treatment is administered and the tuberculosis is controlled. However, pericardial effusion caused by heart failure may recur repeatedly because heart failure itself can also recur. Moreover, pericardial effusion caused by tumors, if the tumors cannot be eradicated, often also recurs.