Which laboratory result would most strongly indicate a biliary obstruction?

Which laboratory result would most strongly indicate a biliary obstruction?

• A. Elevated ALT
• B. Elevated creatinine
• C. Low hemoglobin
• D. Elevated bilirubin

Answer: (D)

Blocking bile flow from the liver causes bilirubin to back up into the bloodstream, so bilirubin levels rise, especially the conjugated form, leading to jaundice. This direct consequence makes elevated bilirubin the strongest indicator of a biliary obstruction among the choices. ALT rises with liver cell injury rather than a blockage of bile flow. Creatinine reflects kidney function, not biliary processes. Low hemoglobin indicates anemia, which isn’t related to biliary obstruction. You might also see alkaline phosphatase and GGT rise with obstruction, but among these options, bilirubin elevation is the most specific signal.

Blocking bile flow from the liver causes bilirubin to back up into the bloodstream, so bilirubin levels rise, especially the conjugated form, leading to jaundice. This direct consequence makes elevated bilirubin the strongest indicator of a biliary obstruction among the choices. ALT rises with liver cell injury rather than a blockage of bile flow. Creatinine reflects kidney function, not biliary processes. Low hemoglobin indicates anemia, which isn’t related to biliary obstruction. You might also see alkaline phosphatase and GGT rise with obstruction, but among these options, bilirubin elevation is the most specific signal.