Introduction to ascites

Ascites is commonly caused by cirrhosis but there are also other causes. In patients with cirrhosis, ascites is related to portal hypertension, low plasma albumin and enhanced kidney retention of sodium. Ascites caused by cirrhosis is suggested by a serum-to-ascites albumin gradient (SAAG) of more than 11 g/L. A SAAG of 11 g/L or less suggests another cause of ascites (eg malignancy, pancreatitis, tuberculosis), or the presence of complications, such as spontaneous bacterial peritonitis or hepatocellular carcinoma.

Large-volume (moderate to severe) ascites is usually obvious on physical examination, but smaller volumes (mild ascites) are often only detected on imaging.