• 01Sep

    How does jaundice occur?

    Jaundice is detected when there is yellow discoloration of the eyes due to deposition of a yellow pigment called bilirubin. The pigment is seen in the white (sclera) of the eyes. If levels of bilirubin in blood are higher, even the skin turns yellow.

    Genesis of bilirubin

    Bilirubin is mainly produced by the breakdown of red blood cells. The life span of a red cell is about 120 days. It is formed mainly in the liver and spleen and is insoluble in water. To be transportable in blood, it has to be soluble. This occurs by conjugation reaction in liver where the bilirubin binds with glucuronic acid. This water soluble is excreted in bile which is stored in gall bladder. Bile is secreted after meals and helps in the digestion of fats. 

    Causes of jaundice

    A lot of diseases can cause jaundice. A careful clinical examination and laboratory examination and modern imaging are required to arrive at the correct diagnosis. Some of the common causes are enumerated below:

    Haemolytic anaemia: there is increased breakdown of red cells, either due to defect in these cells or in association with diseases like malaria. This increased cell turnover results in anaemia and jaundice. In these conditions the bilirubin does not usually become very high (< 5mg /100 ml). This may be associated with presence of pigment stones in the gall bladder. Some of these stones may spill over into the bile passage (bile duct) and result in deep jaundice.

    Drug induced: Many drugs affect the production of bilirubin in the liver and can cause jaundice. Some of these drugs are rifampicin, probenecid.

    Hereditary disorders: Gilbert syndrome, crigler-najjar syndrome, Dubin-Johnson and Rotor syndromes also present with jaundice.

    juandice2Liver disorders: a variety of liver disorders can cause jaundice since liver is involved with the metabolism of bilirubin.

    • Viral hepatitis – infection of liver caused by certain viruses can cause inflammation of liver (hepatitis) and result in jaundice because of its inability to form soluble bilirubin. Infection with Hepatitis A, B, C, D, and E, Epstein-Barr, Cytomegalovirus and Herpes simplex viruses can cause jaundice.
    • Alcohol – alcohol causes direct damage to liver cells resulting in hepatitis.
    • Drug induced hepatitis – acetaminophen, isoniazid.
    • Environmental toxins – Vinyl chloride, Jamaica bush tea (pyrrolizidine alkaloids), Wild mushrooms (Amanita phalloides)
    • Wilson’s disease – it is a genetic disorder in which copper accumulates in liver causing hepatitis. It occurs due to failure to excrete copper in the bile. Liver damage occurs at 3 years of age. Stones in the gall bladder and kidneys are frequently seen in these patients.
    •  Autoimmune hepatitis – it is condition caused by damage to liver cells by body’s own immune cells.

    Obstruction to bile passage: Stones in bile duct, narrowing of duct, blockage by a tumor (gall bladder cancer, cancer of pancreas, cancer of bile duct), chronic pancreatitis.

    • Presence of stones in the bile duct is a very common cause of jaundice. Usually these stone pass from the gall bladder because of their small size or wide opening of duct of gall bladder. They result in pain, fever and jaundice.
    • Cancers usually present with painless jaundice. When the disease becomes advanced, pain may appear due to involvement of adjacent nerves.
    • A lot of drugs can cause stasis or slow down the bile flow. This results in jaundice. The common drugs are anabolic steroids, oral contraceptives, imipramine, cimetidine and erythromycin estolate.

     Jaundice occurs due to multiple disorders. The initial approach is to differentiate the cause as hepatic (due to liver disease) or extra-hepatic (other than liver disease). A logical approach results in finding the cause of jaundice, by a taking medical history, clinical examination, laboratory investigations and appropriate imaging or endoscopy and biopsy. A timely management can prevent permanent liver damage in benign conditions.

    Anna L.

    It’s all about health!
    I have academic background in drugs related Chemical Technology, as well as extensive professional experience in pharma and medical companies. My main area of interest is everyday life medicine. The goal of my articles is to give people informative answers to the questions that bother them, to dispel doubts and some common misbeliefs and also to inspire everyone to keep healthy lifestyle.

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