jaundice

Yellow discoloration of the skin and whites of the eyes caused by an excess of bile pigment in the bloodstream. Approximately 60% of newborn babies exhibit some degree of jaundice, which is treated by bathing in white, blue, or green light that converts the bile pigment bilirubin into a water-soluble compound that can be excreted in urine. A serious form of jaundice occurs in rhesus disease (see rhesus factor).

Bile pigment is normally produced by the liver from the breakdown of red blood cells, then excreted into the intestines. A build-up in the blood is due to abnormal destruction of red cells (as in some cases of anaemia), impaired liver function (as in hepatitis), or blockage in the excretory channels (as in gallstones or cirrhosis). The jaundice gradually recedes following treatment of the underlying cause.