pleural effusion treatment cost in india, Pleural effusion is excess fluid that accumulates between the two pleural layers, the fluid-filled space that surrounds the lungs. Excessive amounts of such fluid can impair breathing by limiting the expansion of the lungs during ventilation.Pleural Effusion (Fluid in the Lungs) is a condition with an abnormal collection of fluid in the Chest Cavity. The pleura is a thin membrane that lines the surface of the lungs and the inside of the chest wall outside the lungs. In pleural effusions, fluid accumulates in the space between the layers of pleura.