Bilirubin testing checks for levels of bilirubin in your blood. Bilirubin (bil-ih-ROO-bin) is an orange-yellow substance made during the normal breakdown of red blood cells. Bilirubin passes through the liver and is eventually excreted out of the body.
Higher than normal levels of bilirubin may indicate different types of liver problems. Occasionally, higher bilirubin levels may indicate an increased rate of destruction of red blood cells (hemolysis).
Why Get Tested :
- or the diagnosis of jaundice.
- To differentiate different types of jaundice.
- For the follow-up of a patient with treatment.
- To assess the progress of the disease.
- This test is done to evaluate the liver functions.
- This is done in a patient with hemolytic anemia in adults.
- It is also done to evaluate the hemolytic anemia in the newborn.
When to Get Tested:
Your doctor may order a bilirubin test if you:
- Show signs of jaundice
- Have anemia, or low red blood cells
- Might be having a toxic reaction to drugs
- Have a history of heavy drinking
- Have been exposed to hepatitis viruses
- Have cirrhosis
You might also have your bilirubin tested if you have symptoms like:
When Bilirubin Test Orderd:
A health practitioner usually orders a bilirubin test in conjunction with other laboratory tests (alkaline phosphatase, AST, ALT) 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.
- Raised Bilirubin is the indicator of liver dysfunction.
- Bilirubin is the basic end product of Hemoglobin metabolism.
- This test is done in the serum of the patient.
- The random sample can be taken and no need for a fasting sample.
- From infants, the blood may be collected from the heel.
- The sample is stable at 4 °C for 3 days and protects it from the light.
Precautions for Sample :
- Avoid hemolysis.
- Avoid shaking of the tube that may lead to inaccurate results.
- Do not expose the tube to light. Exposure to light like the sun or even artificial light may decrease the value.
- If there is a delay in the test then keep the sample away from the light and refrigerate it.
|Age||Premature mg/dL||Full-term mg/dL||Adult mg/dL|
|Cord blood||<2 mg||<2.0|
|0 to 1 day||<8.0||1.4 to 8.7|
|1 to 2 days||<12.0||3.4 to 11.5|
|3 to 5 days||<16.0||1.5 to 12.0|
|5 days to 60 years||0.3 to 1.2|
|60 to 90 year||0.2 to 1.1|
|>90 year||0.2 to 0.9|
Raised Bilirubin level is seen in:
- Some infections, such as an infected gallbladder, or cholecystitis.
- Some inherited diseases, such as Gilbert’s syndrome.
- Although jaundice may occur in some people with Gilbert’s syndrome, the condition is not harmful.
- Diseases that cause liver damage, such as hepatitis, cirrhosis, or mononucleosis.
- Diseases that cause blockage of the bile ducts, such as gallstones or cancer of the pancreas.
- Rapid destruction of red blood cells in the blood, such as from sickle cell disease or an allergic reaction to blood received during a transfusion (called a transfusion reaction).
- Medicines that may increase bilirubin levels. This includes many antibiotics, some types of birth control pills, indomethacin (Indocin), phenytoin (Dilantin), diazepam (Valium), and flurazepam (Dalmane).
Decreased Bilirubin level is seen in:
- Medicines that may decrease bilirubin levels. This includes vitamin C (ascorbic acid), phenobarbital, and theophylline.
Causes of direct hyperbilirubinemia:
- When more than 50% is direct bilirubin.
- Gallbladder tumors.
- Inflammatory scarring or obstruction of extrahepatic ducts.
- Can be resolved by the surgery.
- Dubin-Johnson syndrome.
- Rotor syndrome.
- Drugs may cause cholestasis.
Causes of Indirect hyperbilirubinemia:
- When less than 15 to 20 % is direct bilirubin.
Table showing the Different type of Jaundice and their causes
|Type of Jaundice||Causes||Pathophysiology|
|Unconjugated hyperbilirubinemia||Extravascular hemolysis||Heme is converted to unconjugated bilirubin|
|Right heart failure and Cirrhosis||There is a defect in the delivery of unconjugated bilirubin to liver|
|Hypothyroidism and Crigler-Najjar syndrome||There is a defect in the conjugation of bilirubin in the hepatocytes|
|Drugs like Rifampicin and Gilbert syndrome||There is a defect in the uptake of unconjugated bilirubin into hepatocytes|
|Conjugated hyperbilirubinemia||Mechanical obstruction by tumors, stones or strictures, and primary biliary cirrhosis||There is a defect in the flow of conjugated bilirubin through canaliculi and bile ducts. Called cholestatic jaundice.|
|Drugs like estrogen and cyclosporineDubin-Johnson syndromePregnancy||There is a defect in the transmembrane secretion of conjugated bilirubin into the canaliculus. This is also called hepatocellular jaundice|