What is a pleural fluid analysis?Pleural fluid is a liquid that is located between the layers of the pleura. The pleura is a two-layer membrane that covers the lungs and lines the chest cavity. The area that contains pleural fluid is known as the pleural space. Normally, there is a small amount of pleural fluid in the pleural space. The fluid keeps the pleura moist and reduces friction between the membranes when you breathe.Sometimes too much fluid builds up in the pleural space. This is known as pleural effusion. Pleural effusion prevents the lungs from fully inflating, making it hard to breathe. A pleural fluid analysis is a group of tests that look for the cause of pleural effusion.Other names: pleural fluid aspiration
