Pleural Effusion: An Overview for Primary Care

Pleural effusion is defined as the accumulation of excess fluid in the pleural space, the cavity located between the parietal and visceral pleura of the lungs. This condition can compromise respiratory mechanics and introduces both diagnostic and therapeutic challenges in clinical practice, especially in primary care settings. Pleural effusions are commonly categorized as transudative or exudative based on the pleural fluid’s biochemical properties, with diagnostic thoracentesis serving as a key procedure to determine etiology and guide treatment (Panjwani & Salman, 2019; Brahmbhatt et al., 2024).

Image credit https://en.wikipedia.org/wiki/Pleural_effusion

In the accompanying diagram above , each component of the thoracic anatomy is labeled to illustrate how pleural fluid builds up and creates a pleural effusion:

1. Trachea: Shown in the center at the top, the trachea conducts air from the upper airway down to the lungs.

2. Lung: Represented in gray and enclosed by the pleural membranes. It requires adequate space to expand during breathing.

3. Pleura : The pleura is a two-layered membrane—one layer (the visceral pleura) tightly coats the lung surface, and the other layer (the parietal pleura) lines the inside of the chest wall.

4. 
   

5. Pleural Effusion: Indicated in yellow, this fluid accumulates in the potential space...