Types of Jaundice
Rahul's Noteblog
Notes on Gastroenterology
Types of Jaundice
| Type of Jaundice | Type of Hyperbilirubinemia | Urine Bilirubin | Urine Urobilinogen |
| Hepatocellular | conjugated (direct) | increased | normal |
| Hepatocellular | unconjugated (indirect) | increased | decreased |
| Obstructive | conjugated (direct) | increased | decreased |
| Hemolytic | unconjugated (indirect) | decreased | increased |
Bilirubin is a very important diagnostic tool that can help us differentiate between hemolytic blood diseases and various types of pancreatic and liver diseases. The accumulation of bilirubin in blood is called jaundice, and we shall try to differentiate between the different types of jaundice. You may also be interested in my notes on the physiological formation of bilirubin.
Hemolytic Jaundice:
In hemolytic jaundice, red blood cells are destroyed so quickly, that the liver cannot excrete the unconjugated bilirubin as quickly as it is formed. The large amount of insoluble unconjugated bilirubin flows through the liver directly into the intestines where it is converted into soluble urobilinogen by gut bacteria. Therefore, the plasma concentration of unconjugated bilirubin rises, and the rate of formation of urobilinogen in the intestine increases. Furthermore, urine bilirubin is low (because a large amount of unconjugated is insoluble in urine) and urine urobilinogen is high. Hemolytic jaundice may be seen in sickle cell disease, hereditary spherocytosis, and glucose 6 phosphate dehydrogenase deficiency.
Obstructive Jaundice:
Obstructive jaundice is either caused by damaged hepatocytes (hepatitis) or due to the blockade in the bile ducts (gallstones) or due to cancer in the head of the pancreas. The rate of bilirubin formation and conjugation is normal, but conjugated bilirubin cannot pass from blood into the intestines due to the obstruction. Therefore, the accumulated bilirubin in the blood is conjugated bilirubin. Furthermore, there is increased urine bilirubin (because conjugated bilirubin is soluble in urine), and decreased urobilinogen (because urobilinogen is trapped within the small intestine due to the obstruction). In the end you get to see clay-colored stools, and significant conjugated bilirubin in urine.
Jaundice of Hepatocellular Disease:
In hepatocellular jaundice, the bilirubin may be conjugated or unconjugated, depending upon liver function. There will be increased urinary bilirubin, and normal or decreased urine urobilinogen depending on liver function.
Additional Reading:
Basic Gastroenterology
1. Basic Gastrointestinal Physiology
2. Digestion FAQ, Defecation reflex, etc.
3. Digestion
4. Notes on Functions of the Liver
5. Notes on Jaundice
6. Types of Jaundice
Related Topics
1. Gastrointestinal Disorders
2. Hepatobiliary and Pancreatic Disorders
3. Histology of the Digestive Tract I: Oral Cavity
4. Histology of the Digestive Tract II: Esophagus through Intestines
5. Histology of the Liver, Pancreas, and Gall Bladder
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Page accessed on: July 29, 2010, 11:40 am.