What causes pleural adhesion and thickening?

Pleural adhesion and thickening are primarily caused by pleuritis. Various pathogenic factors continuously irritate the pleura, leading to inflammation of the pleura. The most common factor is infection, in which bacteria or viruses infect the pleural area, causing localized inflammation. Substances secreted during inflammation deposit on the surface of the pleura, including fibrin, which leads to pleural thickening. Additionally, inflammatory tissue can cause adhesions between the parietal and visceral pleura. CT examination may reveal pleural thickening along with signs of indentation and adhesion.