This document discusses pleural effusion, which is an accumulation of fluid in the pleural space between the lungs and chest wall. It can be caused by conditions like heart failure, infections, cancer, or autoimmune disorders. The fluid is classified as a transudate or exudate based on its composition. Symptoms include shortness of breath and chest pain. Diagnosis involves x-rays, ultrasound, or thoracentesis to analyze the fluid. Treatment depends on the underlying cause but may include draining fluid, treating the infection or heart condition, or surgery in severe cases. Nurses monitor for respiratory distress and manage chest tubes if used to drain the fluid.