Which term describes the accumulation of fluid within the peritoneal cavity?

• A. Edema
• B. Pleural effusion
• C. Hydronephrosis
• D. Ascites

Answer: (D)

Ascites is the accumulation of fluid in the peritoneal cavity. The peritoneal space normally contains only a small amount of fluid, but certain conditions disrupt the balance of forces that keep fluid in the vessels and out of the abdomen. Liver disease with portal hypertension raises pressure in the portal venous system, pushing more fluid into the abdominal cavity. At the same time, low levels of albumin reduce the blood’s ability to hold onto fluid (decreased oncotic pressure), allowing fluid to leak into the peritoneal space. Inflammation or infection can increase the permeability of the peritoneal lining, and impaired lymphatic drainage can hinder fluid removal, all contributing to ascites. This is distinct from edema, which is fluid accumulation in tissues (interstitial space) throughout the body; pleural effusion, which is fluid in the pleural space around the lungs; and hydronephrosis, which is dilation of the kidney due to obstruction.