In general, the cost of a thoracentesis kit is about$400, plus other materials, for a total of about$1,000, with some differences in cost that may occur due to different price standards at various levels of hospitals. The main function of thoracentesis is to extract pleural fluid for examination of its properties, as well as chemical testing, microscopic testing and bacteriological testing to clarify the nature of the fluid and thus find the cause of the fluid. The extraction of fluid and gas in the chest cavity can also relieve the pressure of gas and fluid on the lung tissue and allow the lung tissue to reopen, thus relieving the patient of breathing difficulties and other symptoms.