Slideshows Images Quizzes

Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. See additional information.

Definition of Effusion

Effusion: Too much fluid, an outpouring of fluid. For example, a pleural effusion is an abnormal accumulation of fluid in the pleural space between the lungs and the chest wall, while a knee effusion is an abnormal amount of fluid in the knee joint. A hemorrhagic effusion contains blood in the fluid.

Health Solutions From Our Sponsors