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My textbook says that the yellow appearance of a jaundiced person is due to the accumulation of bile pigments in the skin. I am unable to understand why these pigments are not deposited in a healthy person? Please help.

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    $\begingroup$ Because our liver breaks them down and makes sure they are excreted. $\endgroup$ – Chris Jun 11 '15 at 6:40
  • $\begingroup$ @Chris, my question was why couldn't the breakdown(that you are referring to) happen in a healthy person? $\endgroup$ – Razi Alam Jun 11 '15 at 6:44
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    $\begingroup$ The breakdown does happen in a healthy person which is the reason they are not getting yellow. $\endgroup$ – Chris Jun 11 '15 at 7:06
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The yellow color comes from the accumulation of Bilirubin in the body. Bilirubin is a breakdown product of hemoglobin (contained in erythrocytes, also known as red blood cells, and responsible for the oxygen transport in the body). (This is also the reason why bruises get colored, as the blood which was released into the skin gets removed.) As erythrocytes live only for around 120 days, the hemoglobin needs to be recycled at the end of the life cycle, as free hemoglobin is a pretty problematic substance.

The recycling of the erythrocytes happens in the liver, the iron is recycled, and the hemoglobin is split in the globin (which is further broken down into the amino acids) and the heme which is oxidized by the heme oxidase to biliverdin and further by the biliverdin reductase to bilirubin.

As bilirubin is not water soluble it is bound to albumin and released into the bloodstream for the transport to the liver. In the liver this process goes on further until the bilirubin is water soluble and can be released with the bile into the intestine where it is finally excreted. See the image (from here) for an illustration:

enter image description here

If your liver is not working properly (for example due to an infection) the break-down process of the albumin-bound bilirubin is reduced or doesn't work and the yellow bilirubin accumulates in the body until the skin gets yellow. So this indicates a liver malfunction and is usually nothing to take easy.

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