what is jaundice
Jaundice is the yellowish colouring of the skin and sclerae (the white portion of the eyes) that is caused by high levels in blood of the chemical bilirubin( hyperbilirubinemia).
It is not a disease but rather a sign that can occur due to manydiseases. Jaundice can occur in babies, children, and adults. The excess bilirubin level causes the skin, eyes, and mucus membranes in the mouth to turn a yellowish color. Jaundice is often seen in liver disease such as hepatitis or liver cancer . It may also indicate obstruction of the biliary tract, for example by gallstones or pancreatic cancer , or less commonly may be congenital The color of the skin and sclerae vary depending on the level of bilirubin. When the bilirubin level is mildly elevated, they are yellowish and when the bilirubin level is high, they tend to be brown.
what causes jaundice
Jaundice is mainly caused by an increase in the amount of bilirubin in the blood. Bilirubin is a yellowish pigment that is produced from the breakdown of heme (blood), primarily from hemoglobin and red blood cells (RBCs). When red blood cells get old, they are destroyed. Hemoglobin , the iron-containing chemical in red blood cells that carries oxygen, is released from the destroyed red blood cells after the iron it contains is removed. The chemical that remains in the blood after the iron is removed becomes bilirubin. liver remove toxic chemicals or waste products from the blood, and bilirubin is a waste product. The liver removes bilirubin from the blood. After the bilirubin has entered the liver cells, the cells conjugate (attaching other chemicals, primarily glucuronic acid) to the bilirubin, and then secrete the bilirubinglucuronic acid complex into bile. The complex that is secreted in bile is called conjugated bilirubin. The conjugated bilirubin is eliminated in the feces, due to the presesnce of bilrubin in the feces it appears to be yellow in colour.
Jaundice occurs when there is
1) large amount of bilirubin is being produced for the liver to remove from the blood . It commonly occurs in patients with hemolytic anemia have an abnormally rapid rate of destruction of their red blood cells that releases large amounts of bilirubin into the blood
2) There is defect in the liver that prevents bilirubin from being removed from the blood, converted to bilirubin glucuronic acid (conjugated) or secreted in bile
3) There is blockage of the bile ducts that decreases the flow of bile and bilirubin from the liver into the intestines. The bile ducts can be blocked by cancers gall stones, or inflammation of the bile ducts. The decreased conjugation, secretion, or flow of bile that can result in jaundice is referred to as cholestasis: however, cholestasis does not always result in jaundice.
Article publié pour la première fois le 15/09/2016