Your lungs are each surrounded by two layers of membrane. These membranes are called pleura. The space between the layers is called the pleural space. Normally the pleural space has a tiny amount of fluid in it. But excess fluid, blood, pus, or air in the pleural space makes it hard for the lung to expand and makes breathing difficult. A chest tube is a soft, flexible tube put into the pleural space that surrounds the lung. The tube does not go into the lung itself. The tube drains blood, air, or excess fluid. The tube is inserted through a small cut (incision) in the skin.
