What does it mean when you have liquid around your lungs?

Pleural effusion... An accumulation of fluid around the lungs is called a pleural effusion. Effusions can be cause by a number of different disorders including but not limited to: congestive heart failure, pneumonia, malignancy of the lungs / pleura (outer membranes of the lungs), and inflammation of the pleura. Draining the fluid may diminish symptoms and may also help to clarify what is causing the effusion.