Total Bilirubin:

bilirubin is the excretory product formed by catabolism of heme. It is conjugated by the liver and excreted through bile.

Measurement of bilirubin as well as detection of bilirubin and urobilinogen in urine are important tests of liver function.

Bilirubin gets increased during hepatic disorder and the condition is called as hyperbilirubenemia. This condition can lead to yellow colouring of skin and is referred as janundice.

Jaundice is classified into three types:

a. Hemolytic jaundice (pre hepatic) : if the billirubin is increased due to excessive destruction of RBCs due to hemolysis then it is called as hemolytic jaundice.

Cause:

i. Hemolytic anemia

ii. Venoms (snake bite)

b. Hepatic jaundice: if the bilirubin is increased due to liver damage, then it is called as hepatic jaundice.

Cause:

1. Liver cirrhosis
2. Hepatitis
3. Drugs ingestion

c. Obstructive jaundice(post hepatic): if the bilirubin is increased due to the obstruction in the bile duct is is called as obstructive jaundice.

Cause:

1. gall stone
2. Tumors

The conjugated bilirubin is called as direct bilirubin and the unconjugated one is called as indirect bilirubin.