Jaudice is not a disease in itself,but yellowing of the skin and mucous membranes is a sign of abnormal bilirubin metabolism and excretion. Bilirubin is produced from the breakdown of haemoglobin,in conjugated in the liver and excreated in the bile. Conjugation,the process of adding certain groups to the bilirubin molecule,makes it water-soluble and greatly enhances its removal from the blood. Jaudice develops when there is an abnormality of bilirubin processing.
TYPES OF JAUDICE.
1)PRE-HEPATIC JAUDICE.
This is due to increased haemolysis of red blood cells that result in production of excess bilirubin. Because the excess bilirubin is unconjugated it cannot be excreated in the urine,which therefore remains normal in colour.
Neonatal haemolytic jaudice occurs in many babies,especially in those born prematurely where the normal high haemolysis is coupled with shortage of conjugating enzymes in the hepatocytes of the still immature liver.
2)INTRA-HEPATIC JAUDICE.
This is the result of damage to the liver itself by:
A.Viral hepatitis.
B.Toxic substances eg drugs.
D. Cirrhosis
3.POST-HEPATIC JAUDICE.
Causes of obstruction to the flow of bile in the biliary tract included:
a)gallstones in the common bile duct.
b) tumour of the head of the pancreas.
c)fibrosis of the bile ducts,following cholangitis or injury by the passage of gallstones.
EFFECTS OF RAISED SERUM BILIRUBIN.
1)Pruritis(itching).
2) Pale feaces due to absence of stercobilin.
3) Dark urine due to the presence of increased amounts of bilirubin.
