Abstract

An empyema (from Greek ἐμπύημα, "abscess") is a collection or gathering of pus within a naturally existing anatomical cavity. For example, pleural empyema is empyema of the pleural cavity. It must be differentiated from an abscess, which is a collection of pus in a newly formed cavity.

Classification

In human medicine, empyema occurs in:

- the pleural cavity (pleural empyema also known as pyothorax)

- the thoracic cavity

- the uterus (pyometra)

- the appendix (appendicitis)

- the meninges (subdural empyema)

- the joints (septic arthritis)

- the gallbladder