What causes unconjugated jaundice?

Unconjugated hyperbilirubinemia occurs with increased bilirubin production caused by red blood cell destruction, such as hemolytic disorders, and disorders of impaired bilirubin conjugation, such as Gilbert syndrome.

What is unconjugated jaundice?

Unconjugated bilirubin is a waste product of hemoglobin breakdown that is taken up by the liver, where it is converted by the enzyme uridine diphosphoglucuronate glucuronosyltransferase (UGT) into conjugated bilirubin. Conjugated bilirubin is water-soluble and is excreted into the bile to be cleared from the body.

How does unconjugated bilirubin cause jaundice?

Unconjugated bilirubin is hydrophobic, so cannot be excreted in urine. Thus, the finding of increased urobilinogen in the urine without the presence of bilirubin in the urine (due to its unconjugated state) suggests hemolytic jaundice as the underlying disease process.

What happens if unconjugated bilirubin is high?

Elevated levels may indicate liver damage or disease. Higher than normal levels of direct bilirubin in your blood may indicate your liver isn’t clearing bilirubin properly. Elevated levels of indirect bilirubin may indicate other problems.

What does conjugated bilirubin mean?

Once in the liver, bilirubin becomes “conjugated.” This means it is water-soluble and can be excreted. Unconjugated bilirubin is toxic, but conjugated bilirubin is usually not, because it can be removed from the body, as long as nothing is interfering with its removal.

What happens if conjugated bilirubin is high?

Accumulation of bilirubin or its conjugates in body tissues produces jaundice (ie, icterus), which is characterized by high plasma bilirubin levels and the deposition of yellow bilirubin pigments in the skin, sclerae, mucous membranes, and other less visible tissues.

What is conjugated and unconjugated hyperbilirubinemia?

Depending on the form of bilirubin present in serum, hyperbilirubinemia can be further classified as unconjugated (indirect) or conjugated (direct). Unconjugated hyperbilirubinemia (albumin-bound) usually results from increased production, impaired hepatic uptake, and decreased conjugation of bilirubin.

What is the difference between icterus and bilirubin?

Bilirubin is an end product of hemoglobin metabolism. Icterus occurs when bilirubin formation exceeds hepatobiliary excretion.

What is the difference between conjugated and Delta bilirubin?

Note, that there is a third form of bilirubin, called delta bilirubin (or biliprotein), which is conjugated bilirubin bound to proteins. Delta bilirubin increases in serum when hepatic excretion of conjugated bilirubin is impaired (cholestasis) and the liver retains intact conjugation mechanisms.

What is hyperbilirubinemia jaundice?

Introduction Jaundice, also known as hyperbilirubinemia,[1]is a yellow discoloration of the body tissue resulting from the accumulation of an excess of bilirubin. Deposition of bilirubin happens only when there is an excess of bilirubin, a sign of increased production or impaired excretion.