Pleurisy can arise from different causes and take different ways to develop, sometimes with excess fluid in the pleural cavity ("wet pleurisy") and sometimes without ("dry pleurisy"), sometimes accompanied by no pain sometimes very painful. The most common cause of pleurisy is viral infection such as the flu or pneumonia.
There are two kinds of pleurisy. A "primary" pleurisy is an inflammation that happens in the pleural tissues themselves, from a germ that attacked them directly, or from an injury or growth.
A "secondary" pleurisy is caused by another chest disease including:
- pneumonia, in which the germs reach the pleura as well as the lungs themselves,
- lung abscess
- lung cancer
- or almost anything wrong in the chest.