Pleural effusion

Pleural effusion is an accumulation of fluid in the pleural cavity, the space between the membranes that surround the lungs. The fluid may be on one side (unilateral) or both sides of the chest (bilateral).

The fluid may be a mixture of lymphatic fluid and lipids (chylothorax), or it may be watery and serum-like (hydrothorax).

Other resources:

• Pleural effusions
  TheFetus.net
• UOG videoclip: Maternal propranolol treatment for fetal pleural effusion
  Ultrasound in Obstetrics & Gynecology

Updated February 9, 2025