Biliary sludge is mainly seen in the total bilirubin level of biochemical indicators. Other indicators may also look at total bile acids, alkaline phosphatase and glutamyl transpeptidase levels.
Cholestasis can be categorized as intrahepatic or extrahepatic, with intrahepatic including intrahepatic obstructive cholestasis and intrahepatic cholestasis.
In biliary obstruction, pressure rises above the obstruction, bile ducts dilate, small bile ducts and capillary bile ducts rupture, bilirubin enters the bloodstream, and bilirubin increases.
Total bilirubin is the sum of direct and indirect bilirubin levels. When cholestasis is present, all bilirubin markers are increased, but elevated conjugated bilirubin predominates, as does a positive urine bilirubin test, while urobilinogen is decreased or absent.
Total bile acids, alkaline phosphatase and glutamyl transpeptidase levels are also elevated.
In addition to this, cholestasis is accompanied by more specific clinical manifestations. For example, yellowing of the skin and mucous membranes, yellowing of the sclera, itching of the skin, strong tea-colored urine and clay-like stools.
It should be noted that the elevation of these indicators does not necessarily mean cholestasis, but may also be other diseases, which need to make a differential diagnosis according to the clinic.