Red blood cells have a life of about 120 days and at the end of their life cycle they are degraded by the spleen; subsequently, the residues are transported to the liver for metabolism.
Under normal conditions, all the bilirubin produced is eliminated from the body with a mechanism that is in equilibrium: what is produced is also processed to be degraded. However, if you notice a yellowish color of the skin and eyes, we are probably faced with a condition caused by high circulating bilirubin.
High levels of bilirubin in the blood (hyperbilirubinemia) can therefore reflect a problem level
- hepatic, with increased blood concentration of indirect bilirubin,
- or extrahepatic (for example due to obstruction of the bile ducts), with an increase in direct bilirubin.
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The presence of bilirubin in the bile gives the stool its characteristic color; not surprisingly, direct hyperbilirubinemia is often associated with clear stools, due to the non-arrival of bile in the intestine.
Pale stools can also signal a range of severe liver disorders accumulated by blockage of the bile ducts, such as cirrhosis, hepatitis, and liver cancer.
In the presence of liver disease, direct hyperbilirubinemia is accompanied by a greater elimination of the pigment in the urine, which takes on a rather dark color, tending to brown. We would therefore have light stools and dark urine.
The increased destruction of red blood cells, typical for example of so-called haemolytic anemias, can increase the concentrations of direct bilirubin, which is produced in large quantities.
Hyperbilirubinemia is a condition characterized by high levels of bilirubin in the blood. The accumulation of this substance in the tissues is called jaundice and is associated with yellowing of the skin and ocular sclerae (the whites of the eyes).
Direct and total bilirubin blood levels are detected with a simple blood test; alternatively, the test can also be conducted on urine.Indirect bilirubin concentrations are obtained by difference, subtracting the conjugate form from the total value. Results are usually available within a couple of hours.
During the preparation for the exam, the patient is asked not to eat and drink in the four hours preceding the test; the doctor can also impose the suspension of certain drug therapies, in order to avoid possible interference with the test results.
Finally, the bilirubin test is useful for monitoring neonatal jaundice.
such as cirrhosis or hereditary diseases) or as a result of an "increased destruction of red blood cells (haemolysis).
The conjugated bilirubin can increase, however, when the liver is able to metabolize the substance, but is not able to transport it to the bile for this to be removed; in this case, the reason is usually attributable to an "acute hepatitis or a" obstruction of the bile ducts.
