lung

what is a pleural effusion of the lung

[National Jewish]

The lung is covered with a very thin membrane, called the pleura. A similar membrane covers the inside of the chest wall, the ribs and muscles.  As the lungs expand and contract, these lubricated membranes glide over each other. There is normally no space between them. But, in abnormal circumstances such as infection, cancer, trauma, heart failure and sometimes for no obvious reason at all, fluid can build up in the space between these two membranes, sometimes in large amounts, up to 1 to 2 liters. This collection of fluid is called a pleural effusion.  This causes shortness of breath by compressing the lung and making it hard to breathe.  A pleural effusion can be treated surgically to remove the fluid or with chest tubes to drain the fluid and a closed-drainage system to gradually open the lung.