Serum ascites albumin gradient

Dr Henry Knipe and Dr David Carroll et al.

The serum–ascites albumin gradient (SAAG) is the difference between the concurrently obtained serum albumin concentration and the albumin concentration of the ascitic fluid obtained during paracentesis


A difference ≥1.1 grams/deciliter (g/dL) indicates portal hypertension as the likely etiology, whereas a gradient which is <1.1 g/dL implies an etiology that causes increased vascular permeability in the portal system.

Differential diagnosis

A (partial) differential diagnosis of potential etiology, based on the SAAG, is as follows 2:

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Article information

rID: 66981
Section: Pathology
Synonyms or Alternate Spellings:
  • Serum–ascites albumin gradient (SAAG)

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Cases and figures

  • Case 1: pancreatic ascites
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  • Case 2: tuberculous peritonitis
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