Direct bilirubin in the blood is one of the types of important bile tetrapyrroles - pigments. In addition to direct bilirubin, there is another type - indirect. First of all, let us recall what bilirubin actually is.
An increase in the concentration of bilirubin in the blood serum above 17.1 μmol/l is called hyperbilirubinemia. This condition may result from the formation of bilirubin in quantities exceeding the ability of the normal liver to excrete it; liver damage that disrupts the excretion of bilirubin in normal quantities.
Bile pigments are the breakdown products of hemoglobin and other chromoproteins - myoglobin, cytochromes and heme-containing enzymes. Bile pigments include bilirubin and urobilin bodies - urobilinoids.
