Jaundice, also known as hyperbilirubinemia, is caused by an excess of bilirubin in the blood and results in a yellow discoloration of the skin and eyes. It can be categorized as pre-hepatic, hepatic, or post-hepatic based on where the underlying disorder occurs in the pathway of bilirubin metabolism and excretion. Pre-hepatic jaundice is caused by issues prior to the liver like hemolytic anemias. Hepatic jaundice results from liver disease or drugs affecting the liver. Post-hepatic jaundice is due to gallstones or other issues blocking bile ducts after the liver. Laboratory tests can help distinguish between the types

1. Jaundice (Hyperbilirubinemia)
• The word jaundice comes from French word jaune which means
yellow.
• Jaundice or icterus is used to describe the yellow discoloration of skin
, eyes and mucous membranes most resulting from retention of
bilirubin.
• The upper limit of normal for total bilirubin is 0.2 to 1.2mg/dl,
jaundice is not noticeable until bilirubin levels reached to 3 to 5
mg/dl.
• Icteric term commonly used in clinical lab refer to a serum or plasma
with yellow discoloration.

2. Types of Hyperbilirubinemia
• Unconjugated hyperbilirubinemia
• Conjugated hyperbilirubinemia

3. • Jaundice is most commonly based on the site of the disorder
• Pre-hepatic jaundice
• Hepatic jaundice
• Post-hepatic jaundice

4. Prehepatic jaundice
• Occurs when the problem causing the jaundice occurs prior to liver
metabolism.
• When an increased amount of bilirubin is presented to liver such as in
acute and chronic hemolytic anemias.
• The liver responds by functioning at max capacity therefore people
with this type of jaundice rarely have bilirubin levels that exceed 5
mg/dl because the liver is capable of handling the over load. This type
of jaundice also referred to as unconjugated hyperbilirubinemia.

5. Causes of Pre-hepatic jaundice
• Hemolysis
• Large hematoma
• Ineffective erythropoiesis

6. Hepatic jaundice
• It occurs when the primary problem causing the jaundice resides in
liver (intrinsic liver defect or disease).
• Causes of hepatic jaundice
• Drugs e.g. rifampicin which interfere with bilirubin uptake
• Prematurity
• Hepatitis viral or drug induced
• Gilberts syndrome
• Crigler-najjar syndrome
• Dobin-johson syndrome
• Rotors syndrome

7. • Impaired excretion
• Hepatitis
• Cirrhosis
• Infiltrations e.g. lymphoma,
• Biliary atresis
• Tumors
• Extrahepatic sepsis
Causes of hepatic jaundice

8. Post-hepatic causes
• Gallstones
• Biliary stricture
• Carcinoma of pancreas of biliary tree
• cholangitis

9. Laboratory findings in hemolytic jaundice
(prehepatic )
• Hemoglobin low
• RBC count low
• Retic count increase
• Total bilirubin high
• Unconjugated bilirubin high rarely> 100umol/L except in neonates
• Conjugated bilirubin normal
• Plasma enzymes AST, LDH slightly increased
• Plasma haptoglobin decreased
• Mild macrocytosis
• Polychromasia

10. • ALP normal
• Gamma GGT Normal
• PT normal
• 5 nucleotidase normal
• Urine Urobilinogen increased than normal
• Urinary bilirubin absent

11. Lab findings in hepatic jaundice
• In acute viral hepatitis
• No features of hemolysis
• Total bilirubin will increase +++
• Unconjugated bilirubin mildly increase
• Conjugated bilirubin +++
• Level of aminotransferases
• They may be 20 times the URL in patients with hepatitis
• Prothrombin time prolonged

12. • If hepatocellular damage is for a very long time than serum albumin
will decrease
• In acute hepatitis serum albumin is normal
• Serum ALP slightly increase
• Gamma GGT +
• 5NT+
• Urobilinogen normal increase or decreased
• Urine bilirubin is increased

13. Lab findings in obstructive jaundice
• Total bilirubin +++
• Unconjugated bilirubin ++
• Conjugated bilirubin ++++
• Markers of hepatic injury
• AST ALT will increase
• SALP GGT 5-NT strongly increase
• Urine Urobilinogen absent
• Urinary bilirubin increase
• Dark urine
• Clay colored stool