In fact, the scientific name for pleural effusion is pleural cavity effusion. There is a potential cavity between the lung and the chest wall, and if fluid collects inside this cavity, it is called pleural effusion. There are many causes and many classifications, and pleural effusions are often classified as leaking fluid, exudate, and also pus, hemothorax, and celiac disease. Leaky fluid is often due to some obstructive problems, such as circulatory system diseases, such as congestive heart failure, constrictive pericarditis, obstruction of the superior vena cava, and these conditions. Exudate is due to some inflammation or tumor or tuberculosis. Hemothorax is due to the rupture of some blood vessels in the chest cavity and some trauma. Suppurative chest is due to infection secondary to pleural effusion, especially staphylococcal infection, where there is pus inside the pleural effusion and pus accumulates. Celiac disease is often caused by blockage of the lymphatic vessels in the chest. There are many causes of lymphatic vessel blockage, such as infection with parasites, tumors can also cause lymphatic bone blockage, and rupture of lymphatic vessels due to celiac disease. Therefore, pleural effusion is not an individual disease, but a comprehensive disease manifestation that may be caused by different etiologies, and the main thing is to do scientific treatment for the primary disease.