Lung cancer pleural effusion grows faster compared to benign diseases, than tuberculous pleurisy, pneumonia-like pleural effusion. Because lung cancer is a malignant tumor, both pleural effusion and masses grow faster compared to other diseases. Therefore, patients may start with a small amount of pleural effusion, and most of them may grow very fast in half a month or a month without effective treatment, causing shortness of breath, wheezing and inability to lie down. However, if the diagnosis of lung cancer pleural effusion is made, after effective treatment, including systemic treatment, local treatment of pleural effusion, pumping of pleural effusion, and local injection of corresponding drugs in the chest cavity if necessary, the pleural effusion can be controlled for most patients. Although the growth is relatively fast, most of them can be controlled through effective treatment.