BIL-T | Total Bilirubin

Total bilirubin (BIL-T) is a blood test that measures the total amount of bilirubin, including both direct (conjugated) and indirect (unconjugated) bilirubin. Bilirubin is a bile pigment formed in the body during the natural breakdown of erythrocytes, then metabolized in the liver and excreted with bile. It is produced by the liver, spleen, and bone marrow, so any dysfunction of these organs may affect the concentration of bilirubin in the blood.

Increased total bilirubin levels in the blood may indicate hemolysis, liver dysfunction, or biliary obstruction. Clinically, it is important in evaluating jaundice, and together with the differentiation of direct and indirect bilirubin, it helps to determine the type of jaundice (prehepatic, hepatic, or posthepatic).

Test principle: In a biochemical blood test, the total bilirubin level is determined using the spectrophotometric method. If necessary, direct bilirubin is additionally tested, and indirect is calculated by subtracting direct from the total bilirubin level.

Recommendations:

• It is recommended to perform this test in cases of jaundice, yellowing of the lower eye whites, symptoms of liver disease, or suspected hemolysis.
• It is also useful in diagnosing Gilbert's syndrome, Dubin-Johnson syndrome, Crigler–Najjar syndrome, obstructive jaundice, biliary tract stones, B12 deficiency anemia, or viral hepatitis.
• Test results must be evaluated together with other liver function indicators (ALT, AST, GGT, ALP) and clinical symptoms.
• Before the test, it is recommended to fast for 8–12 hours, avoid physical exertion and alcohol.
• It can be performed periodically to monitor the course of liver disease or evaluate treatment effectiveness.