Serum-Ascites Albumin Gradient (SAAG)

Determines etiology of ascites by differentiating portal hypertensive from non-portal hypertensive causes.

g/dL

Serum albumin concentration

g/dL

Ascitic fluid albumin concentration

Clinical Notes & Warnings

  • Simultaneous samples required for accurate interpretation.
  • High SAAG confirms portal hypertension but does not indicate specific cause.
  • Values between 1.0 and 1.1 may be equivocal.
  • Serum and ascites albumin must be measured using the same assay.

SAAG is more accurate than total protein classification. Portal hypertensive ascites is associated with complications like varices and SBP.