Bilirubin

Definition

Bilirubin is a yellow compound formed during the breakdown of red blood cells and is processed by the liver for excretion. Elevated levels can indicate liver dysfunction or bile duct obstruction.

5 Must Know Facts For Your Next Test

1. Bilirubin is produced from the degradation of hemoglobin in red blood cells.
2. In viral infections of the gastrointestinal tract, elevated bilirubin levels can indicate liver involvement or damage.
3. Hyperbilirubinemia, or high bilirubin levels, can lead to jaundice, characterized by yellowing of the skin and eyes.
4. Direct (conjugated) bilirubin is processed by the liver and excreted in bile, while indirect (unconjugated) bilirubin circulates in the bloodstream before reaching the liver.
5. Certain viruses, such as Hepatitis A, B, and C, can cause elevated bilirubin levels due to liver inflammation.

Review Questions

• What are the two types of bilirubin and how do they differ?
• How does hyperbilirubinemia manifest clinically?
• Which viral infections can lead to elevated bilirubin levels?

Related terms

Jaundice:

A condition characterized by yellowing of the skin and eyes due to high bilirubin levels.

Hepatitis:

Inflammation of the liver often caused by viral infections that can affect bilirubin processing.

Hemolysis:

The destruction of red blood cells which increases production of bilirubin.