Bilirubin is a yellowish substance derived from the breakdown of red blood cells.
She circulates in the blood in an insoluble form (indirect bilirubin), which is excreted in bile, or in a soluble form with certain proteins (direct bilirubin), which can be eliminated from the body through bile and excreted in the intestine.
High levels of this substance can cause jaundice, a condition in which the skin and eyes become yellowish. This can also occur in certain diseases that affect the liver, since this region is where it is processed and excreted from the body.
Usually its total levels are measured from blood samples.