Pleurodesis is a medical procedure used to treat conditions that cause fluid buildup in the chest cavity, such as pleural effusion or pneumothorax. During the procedure, a substance, often a type of powder, is introduced into the pleural space, which is the area between the lungs and the chest wall. This substance irritates the lining of the lungs and chest, causing them to stick together and preventing further fluid accumulation. The procedure can be performed using a thoracoscopic approach, where a small camera and instruments are inserted through tiny incisions, or through a chest tube. Pleurodesis is generally considered safe, but like any medical procedure, it carries some risks, including infection or pain.