Know About Bilirubin Total, Direct, Indirect (serum)
A bilirubin test measures the amount of bilirubin in your blood. It?s used to help find the cause of health conditions like jaundice, anemia, and liver disease.Bilirubin is an orange-yellow pigment, a waste product primarily produced by the normal breakdown of heme. Heme is a component of hemoglobin, which is found in red blood cells (RBCs). Bilirubin is ultimately processed by the liver to allow its elimination from the body. This test measures the amount of bilirubin in the blood to evaluate a person's liver function or to help diagnose anemias caused by RBC destruction (hemolytic anemia).
RBCs normally degrade after about 120 days in circulation. As heme is released from hemoglobin, it is converted to bilirubin. This form of bilirubin is also called unconjugated bilirubin. Unconjugated bilirubin is carried by proteins to the liver; there, sugars are attached (conjugated) to bilirubin to form conjugated bilirubin. Conjugated bilirubin enters the bile and passes from the liver to the small intestines; there, it is further broken down by bacteria and eventually eliminated in the stool. Thus, the breakdown products of bilirubin give stool its characteristic brown color.
A small amount (approximately 250 to 350 milligrams) of bilirubin is produced daily in a normal, healthy adult. Most (85%) of bilirubin is derived from damaged or degraded RBCs, with the remaining amount derived from the bone marrow or liver. Normally, small amounts of unconjugated bilirubin are released into the blood, but virtually no conjugated bilirubin is present. Both forms can be measured or estimated by laboratory tests, and a total bilirubin result (a sum of these) may also be reported.
If the bilirubin level increases in the blood, a person may appear jaundiced, with a yellowing of the skin and/or whites of the eyes. The pattern of bilirubin test results can give the health practitioner information regarding the condition that may be present. For example, unconjugated bilirubin may be increased when there is an unusual amount of RBC destruction (hemolysis) or when the liver is unable to process bilirubin (i.e., with liver diseases such as cirrhosis or inherited problems). Conversely, conjugated bilirubin can increase when the liver is able to process bilirubin but is not able to pass the conjugated bilirubin to the bile for removal; when this happens, the cause is often acute hepatitis or blockage of the bile ducts.
Increased total and unconjugated bilirubin levels are relatively common in newborns in the first few days after birth. This finding is called ""physiologic jaundice of the newborn"" and occurs because the newborn's liver is not mature enough to process bilirubin yet. Usually, physiologic jaundice of the newborn resolves itself within a few days. However, in hemolytic disease of the newborn, RBCs may be destroyed because of blood incompatibilities between the baby and the mother; in these cases, treatment may be required because high levels of unconjugated bilirubin can damage the newborn's brain.
A rare (about 1 in 10,000 births) but life-threatening congenital condition called biliary atresia can cause increased total and conjugated bilirubin levels in newborns. This condition must be quickly detected and treated, usually with surgery, to prevent serious liver damage that may require liver transplantation within the first few years of life. Some children may require liver transplantation despite early surgical treatment.
Total Bilirubin; TBIL; Neonatal Bilirubin; Direct Bilirubin; Conjugated Bilirubin; Indirect Bilirubin; Unconjugated Bilirubin; Bilirubin - blood.
Jaunduce; Bacteria; Liver Diseases; Cirrhosis; Hepatitis; Gallstones and Haemolytic Anaemia.
To screen for or monitor liver disorders or hemolytic anemia; to monitor neonatal jaundice. When you have signs or symptoms of liver damage, liver disease, bile duct blockage, hemolytic anemia, or a liver-related metabolic problem, or if a newborn has jaundice.
A health practitioner usually orders a bilirubin test in conjunction with other laboratory tests (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase) when someone shows signs of abnormal liver function. A bilirubin level may be ordered when a person:
Shows evidence of jaundice.
Has a history of drinking excessive amounts of alcohol.
Has suspected drug toxicity.
Has been exposed to hepatitis-causing viruses.
Other symptoms that may be present include:
Dark, amber-colored urine.
Abdominal pain and/or swelling.
Fatigue and general malaise that often accompany chronic liver disease.
Measuring and monitoring bilirubin in newborns with jaundice is considered standard medical care.
Tests for bilirubin may also be ordered when someone is suspected of having (or known to have) hemolytic anemia as a cause of anemia. In this case, it is often ordered along with other tests used to evaluate hemolysis, such as complete blood count, reticulocyte count, haptoglobin, and LDH.