What Is Bilirubin Test?
Bilirubin test is a routine blood test. Bilirubin blood test measures the amount of bilirubin in the blood. It is a useful test to find the cause of jaundice, liver disease, anemia, etc.
Bilirubin forms as a result of breakdown of red blood cells as a normal body process. It is an orange yellow pigment. The liver takes this bilirubin and upon some chemical changes ultimately most of it passes through our stool.
Bilirubin is found in bile, the fluid that helps in food digestion. When the liver is healthy, the liver removes most of the bilirubin from the body. When the liver is damaged, bilirubin can leak out from the liver and comes into blood.
Too much bilirubin in the blood causes jaundice.
Here it is important to mention that many newborn babies get jaundice after birth because their liver are not mature enough to remove all the bilirubin.
Newborn jaundice is usually harmless and gets cleared within a few days. In some cases, high bilirubin level in the blood causes brain damage, so as a precaution, infants should be tested for bilirubin level.
When the level of bilirubin in our blood goes up, it can be either as a result of excessive breakdown of RBC at an unusually high rate or the liver became uncapable to chemically change the bilirubin and clear it from the blood.
Sometimes, there is a problem in the pathway that gets the bilirubin from the liver to the stool.
Bilirubin Test Purpose
- To diagnose and monitor liver disease and bile duct diseases such as cirrhosis, hepatitis, gallstones, etc. especially in children and adults.
- To diagnose hemolytic anemia. In case of hemolytic anemia, the red blood cells are destroyed earlier and faster than their production.
- To determine if sickle cell disease is present or not.
- To diagnose if there is blockage of structure that helps to carry bile from the liver
High bilirubin level causes yellowish discoloration of the eye and the skin. This condition is commonly known as jaundice.
Bilirubin Test Procedure
Just like other blood tests ( FPG, RBC, Platelets, etc.), blood is drawn from one vein (preferably vein of the arm). This sample of blood is used to determine the test result. No special precautions are needed for this test.
Certain medicines may affect the test results. So it is highly important to mention the medicines that one is currently taking.
Certain foods can cause higher bilirubin level. So give your healthcare provider a thorough history about your food and lifestyle.
Who Should Get The Bilirubin Test
Bilirubin test is recommended in the following situations
- Presence of signs and symptoms of jaundice
- Presence of anemia, low red blood cells.
- Heavy drinking history
- Having toxic drug reactions
- Have signs and symptoms of liver disease such as cirrhosis
- Have been exposed to hepatitis viruses
The symptoms that need bilirubin test are the following
- Dark urine
- Clay colored stool
- Nausea, vomiting
- Abdominal swelling and pain
Here it is important to mention that bilirubin in urine is also an important test to diagnose different conditions.
Bilirubin Test Result :
Bilirubin test measures total bilirubin in the blood. Test result also gives two different types of bilirubin levels- Conjugated bilirubin and Unconjugated bilirubin.
Conjugated bilirubin (direct bilirubin):
This type of bilirubin goes to the liver from the blood and undergoes some chemical reaction. Next, it goes to the intestine from the liver and after that, it is removed from the stool.
Unconjugated bilirubin (indirect bilirubin):
This type of bilirubin forms as a result of red blood cell breakdown.
Adults over 18 years of age, normal total bilirubin level is upto 1.2 mg/dL.
People under 18 years of age, the normal total bilirubin level is 1 mg/dL.
Conjugated bilirubin normal level should be less than 0.3 mg/dL.
Men usually have higher bilirubin levels than women.
High Total Bilirubin Causes
The causes of high total bilirubin are the following
- Viral hepatitis
- Alcoholic liver disease
- Drug reactions
- Gilbert syndrome – in this condition, there is deficiency of enzyme that helps to break down bilirubin.
- Very strenuous exercise can cause rise of bilirubin levels in the blood.
Low Bilirubin Level Causes
- Caffeine, barbiturates, penicillin, NSAIDs such as salicylates can lower the bilirubin level.
Lower than normal bilirubin level is not a problem.
Newborn High Bilirubin Level
In case of newborn, high bilirubin level that dont comes back to normal within a few days to 2 weeks may be sign of
- Blood type incompatibility between mother and the child
- Inherited infection
- Liver disease
- Lack of oxygen
- Blood transfusion reaction