Overview & Description
A bilirubin test measures the amount of bilirubin in the blood.Hemoglobin is the protein that binds oxygen in red blood cells. When hemoglobinbreaks down, it produces bilirubin. The liver processes bilirubin. If liver cells aredamaged, bilirubin can escape into the bloodstream. Indirect or unconjugatedbilirubin tests measure the bilirubin that has just been made by the breakdownof hemoglobin in the body. Once bilirubin has been processed in the liver, itcan be measured as direct or conjugated. Sometimes the total amountof bilirubin in the blood is measured.
Who is a candidate for the test?
The bilirubin test is often done when a doctor suspects liver orgallbladder disease.The person may have jaundice,which causes yellowed eyes and skin. A buildup of bilirubin causes jaundice.
How is the test performed?
To measure bilirubin levels, a lab technician takes a blood samplefrom a vein in the forearm or hand. First, he or she cleans the skin over the veinwith an antiseptic. Next, a rubber tube called a tourniquet is wrappedaround the upper arm. This restricts blood flow in the veins in the lower arm.And that causes them to enlarge. A fine needle is gently inserted into theenlarged vein, and the tourniquet is removed. Blood flows from the vein throughthe needle into a vial. After the needle is withdrawn, the technician coversthe puncture site with a bandage.
Preparation & Expectations
What is involved in preparation for the test?
Generally, nothing is required to prepare for a bilirubin test.
Results and Values
What do the test results mean?
Normal values for total bilirubin are between 0.3 and 1.2 mg/100 ml.Normal conjugated or direct bilirubin levels should be between 0.0 and 0.2 mg/100 ml.Abnormal bilirubin levels can be found in many disorders, including:
Article type: xmedgeneral