Causes of Jaundice
In this article 13 important causes of jaundice are discussed.
Jaundice is characterised by a yellowing of the skin, eye whites, and body fluids. It is caused by an increase in bilirubin levels in the blood. Bilirubin is a yellowish pigment produced by the breakdown of heme, most notably haemoglobin and red blood cells (RBCs). Bilirubin is transported by the blood to the liver, where it is processed and excreted in bile. Bile is a thick, yellow-green-brown fluid secreted into the upper small intestine (duodenum) to eliminate waste products (such as bilirubin and excess cholesterol) and aid in fat digestion.
Jaundice can occur as a result of increased red blood cell breakdown, inherited changes in bilirubin metabolism, liver disease or damage, or whenever there is an interference with bile excretion.
Increased production of bilirubin
There are several unusual conditions that cause bilirubin overproduction. In these conditions, bilirubin levels in the blood are usually only mildly elevated, and the resulting jaundice is usually mild and difficult to detect. These conditions include: 1) rapid destruction of red blood cells (referred to as hemolysis), 2) a defect in red blood cell formation that results in an excess of haemoglobin in the bone marrow (referred to as ineffective erythropoiesis), and 3) absorption of large amounts of haemoglobin when there has been significant bleeding into tissues (e.g., from hematomas, collections of blood in the tissues).
Acute inflammation of the liver
Any condition that causes the liver to become inflamed can impair the liver’s ability to conjugate (attach glucuronic acid to) and secrete bilirubin. Acute viral hepatitis, alcoholic hepatitis, and Tylenol-induced liver toxicity are common examples.
Chronic liver conditions
Chronic inflammation of the liver can result in scarring and cirrhosis, as well as jaundice. Chronic hepatitis B and C, alcoholic liver disease with cirrhosis, and autoimmune hepatitis are common examples.
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Liver infiltrative disorders
Infiltrative liver diseases are conditions in which the liver becomes infiltrated with cells or substances that do not belong there. The most common example is cancer that has spread to the liver, usually from cancers in the abdomen. A few uncommon causes include diseases in which substances accumulate within the liver cells, such as iron (hemochromatosis), alpha-one antitrypsin (deficiency), and copper (Wilson’s disease).
Biliary duct inflammation
Inflammation of the bile ducts caused by diseases such as primary biliary cirrhosis or sclerosing cholangitis, as well as some drugs, can stop the flow of bile and the elimination of bilirubin, resulting in jaundice.
Bile duct obstruction
Gallstones and pancreatic cancer are the most common causes of bile duct blockage. Cancers of the liver and bile ducts are less common causes.
Many drugs have the potential to cause jaundice and/or cholestasis. Some drugs, like viruses, can cause liver inflammation (hepatitis). Other medications can cause bile duct inflammation, resulting in cholestasis and/or jaundice. Drugs may also directly interfere with the chemical processes that occur within the cells of the liver and bile ducts, which are in charge of the formation and secretion of bile to the intestine. As a result, bile constituents such as bilirubin are retained in the body. Estrogen is the best example of a drug that causes this latter type of cholestasis and jaundice.
There are several rare genetic disorders that cause jaundice from birth. CriglerNajjar syndrome is caused by a defect in bilirubin conjugation in the liver caused by a decrease or absence of the enzyme responsible for conjugating glucuronic acid to bilirubin. Dubin-Johnson and Rotor’s syndromes are caused by abnormal bilirubin secretion into the bile. Gilbert’s syndrome, which affects about 7% of the population, is the only common genetic disorder that can cause jaundice. Gilbert’s syndrome is caused by a slight decrease in the activity of the enzyme responsible for glucuronic acid conjugation to bilirubin.
Bile duct developmental abnormalities
In rare cases, the bile ducts do not develop normally and the flow of bile is disrupted. Jaundice is a common occurrence. These diseases are usually present from birth, though some may not be recognised until childhood or even adulthood. Bile duct cysts (choledochal cysts) are one type of developmental abnormality. Caroli’s disease is another example.
Most of the diseases discussed previously can affect women during pregnancy, but there are some pregnancy-specific causes of jaundice.
Cholestasis of pregnancy is a rare condition that affects pregnant women in their third trimester. Cholestasis is frequently accompanied by itching but rarely results in jaundice. Itching can be excruciating, but there is relief (ursodeoxycholic acid or ursodiol). Pregnant women with cholestasis usually do well, though they are more likely to develop gallstones. More importantly, there appears to be an increased risk of developmental abnormalities in the foetus. Pregnancy cholestasis is more common in certain populations, particularly in Scandinavia and Chile, and it tends to worsen with each subsequent pregnancy.
Pre-eclampsia, also known as toxaemia of pregnancy, is a disease that occurs during the second half of pregnancy and affects several body systems, including the liver. It can cause high blood pressure, fluid retention, kidney damage, anaemia, and a decrease in platelet count due to the destruction of red blood cells and platelets. It frequently causes issues for the foetus. Although bilirubin levels in the blood are elevated in pre-eclampsia, they are typically mildly elevated, and jaundice is uncommon. Preeclampsia is usually treated by delivering the foetus as soon as possible if the foetus is mature.
Pregnancy-related acute fatty liver
Acute fatty liver of pregnancy (AFLP) is a serious pregnancy complication with an unknown cause that is frequently associated with preeclampsia. It occurs late in pregnancy and causes liver failure. It is almost always reversible if the foetus is delivered immediately. Infant mortality is at an all-time high. Jaundice is common in AFLP, but it is not always present. Treatment typically entails delivering the foetus as soon as possible.
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