The Fractional Excretion of Urea (FEUrea) test is conducted to identify the underlying cause of acute kidney injury (AKI). Additionally, the test is employed as a marker for tubular injury, aiding in the differentiation between acute tubular necrosis (ATN) and non-ATN. Healthcare professionals utilize this test within the initial 24 hours of admission for patients with decompensated cirrhosis and ascites.