In normal situation, the body gets rid of all old red blood cells while replacing them with the new blood cells. The bilirubin or a yellow pigment will be left behind after this process. The bile which is mixed with the feces after this process will ensure the elimination of the bilirubin in the feces.
Any problem, disorder and condition that will cause the problem in the above process will make the bilirubin to build up in the blood system. The causes of jaundice are different in adult, in children or in new baby born.
In the newborn babies, the jaundice is common and in normal circumstances it is not serious. It gets disappeared within two weeks. This is because when a woman is pregnant, her liver helps the baby to process the bilirubin but when the child is born, the child liver will take time to learn how to process the bilirubin. This will result in yellowing of the eyes and of the skin in the new baby born. However if the jaundice in the child is caused by the infection, blood disorder, biliary atresia and liver disease can cause serious problem in the baby.
The jaundice in the adult can be caused by the bile duct obstruction or narrowing caused by pancreatitis or gallstones, Cancer of the pancreas or liver, cirrhosis, drug induced cholestasis, hepatitis, malaria, ischemic hepatocellular or obstruction of bile duct caused by the pregnancy. Sometime the jaundice can be caused by hemolytic anemia or sickle cell anemia.