What condition is characterized by fluid accumulation between pleural spaces?

Pleural effusion is accurately described as the condition characterized by fluid accumulation in the pleural space, which is the area between the layers of pleura surrounding the lungs. This condition can result from various underlying issues, such as heart failure, infections, or malignancies, leading to excess fluid production or decreased fluid absorption.

Pneumonia typically involves inflammation and infection of the lung tissue itself rather than fluid accumulation in the pleural space. Pleurisy refers to inflammation of the pleura, often resulting in sharp chest pain, but it does not specifically indicate the presence of excess fluid. Bronchitis is an inflammatory condition affecting the bronchial tubes and does not involve the pleural space. Thus, the identification of pleural effusion as the answer directly correlates with its defining characteristic of fluid buildup in the pleural cavity.