font size

Definition of Effusion

Effusion: Too much fluid, an outpouring of fluid. A hemorrhagic effusion is one that has blood within the fluid. A pericardial effusion is an outpouring of fluid within the fibrous sac (the pericardium) that surrounds the heart. The lungs are covered by two-layered membranes which are called the pleura. A pleural effusion involves the presence of an excessive amount of pleural fluid (between the two layers of the pleural membranes). The term "effusion" comes from the Latin "effusio" meaning a pouring out.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=7016
Last Editorial Review: 10/4/1998

Drug Medical Dictionary of Terms by Letter

Top RxList Drug News

Heart Health

Get the latest treatment options.