Contributed by – Healthians Team
What is the Bilirubin direct serum test?
A bilirubin blood test is also known as Total serum bilirubin and TSB. It measures the amount of bilirubin present in your blood. Bilirubin is a yellowish substance produced when your body undergoes the process of breaking down red blood cells. Bilirubin is found in bile which is a fluid present in your liver that helps you digest food. If your liver is in a healthy state, then it will remove most of the bilirubin from your body. In case your liver is damaged then bilirubin can leak out into your blood. When an excess of bilirubin gets into your bloodstream it can cause jaundice which is a condition that causes your skin and eyes to turn yellow. Signs of jaundice along with a bilirubin blood test can help your doctor diagnose if you are suffering from any liver ailment.
Who should get the test?
A bilirubin blood test is used to check the wellbeing of your liver. It is usually used to aid the diagnosis of jaundice in newborns. Some healthy babies do get jaundice as their livers aren’t mature enough to get rid of excess bilirubin. This condition found in newborns is generally harmless. However, in certain cases these high bilirubin levels can cause brain damage therefore infants are tested as a precautionary measure.
Your doctor might want to perform blood tests or an ultrasound if high levels of bilirubin are detected in your blood. In an adult, high bilirubin may be due to liver ailments, bile ducts or gallbladder. The examples include liver diseases, like hepatitis, Gilbert’s syndrome which is a genetic disease, cirrhosis which is a condition that scars the liver, biliary structure in which a portion of the bile duct is too narrow to allow fluid to pass, cancer of the gallbladder or pancreas, gallstones and drug toxicity.
Why is the test needed?
Your doctor might prescribe a bilirubin blood test if you have signs such as jaundice, dark urine and stomach pain. This could indicate conditions such as hepatitis, cirrhosis and other liver diseases. This test is conducted to find out if there is any blockage in the structures that carry bile from your liver. It can also be used to monitor an existing liver disease and diagnose disorders related to the production of red blood cells. High bilirubin levels in your bloodstream might be a sign of gallbladder disease and a condition called hemolytic anaemia.
What does the test result mean?
High bilirubin levels indicate that your liver isn’t working properly. However, abnormal results don’t always indicate a medical condition. This can also be caused by medications, certain foods or strenuous exercises. In a child or adult, normal values of direct bilirubin are in the range of 0–0.4 milligrams per deciliter (mg/dL). Normal values of total bilirubin are in the range of 0.3–1.0 mg/dL.
In a newborn, presence of higher bilirubin is considered normal due to the stress of birth. Normal indirect bilirubin would be under 5.2 mg/dL within the first 24 hours of birth. However, many newborns have some kind of jaundice and bilirubin levels that rise above 5 mg/dL within the first few days after birth.
How is the test done?
A needle is inserted into the vein of the arm and blood is drawn. To prepare yourself for the test you are not supposed to eat or drink anything other than water four hours prior to your test. You can drink usual amount of water before going to the lab. You might be asked to stop certain medications before the test is performed. Antibiotics such as penicillin G, sedatives like phenobarbital and diuretics such as furosemide are drugs that can affect bilirubin levels.
