Bilirubin, a yellowish pigment found in bile and in fluid state, is made by the liver. Every day new blood cells substitute a small amount of older red blood cells. Bilirubin is left behind after those older blood cells are removed. The liver assists breaking down bilirubin to be removed in the stool from the body. Large amounts of bilirubin in the blood can lead to jaundice.
Direct bilirubin (congugated bilirubin) – the test result that detects bilirubin level
Indirect bilirubin (uncongugated bilirubin) – total bilirubin minus direct bilirubin
It is normal to have some bilirubin in blood.
The test results may vary slightly amongst laboratories, typically for male adult. Slight difference in normal results is expected for women and children. Furthermore the test results may be influenced by certain foods, medications or strenuous exercise.
Causes of Elevated level of bilirubin
Elevated bilirubin level may be caused by infections, such as an infected gallbladder, or cholecystitis 膽囊炎. Inherited diseases, such as Gilbert’s syndrome 遺傳性疾病，如 Gilbert 綜合徵 an diseases that cause liver damage, such as hepatitis, cirrhosis, or mononucleosis 單核細胞增多
Cause of Low levels of bilirubin
Medicines decrease bilirubin levels, such as vitamin C, phenobarbital 苯巴比妥 and theophylline 氨茶鹼.
Causes Affecting the Test Results
- Caffeine which can lower bilirubin levels.
- Fasting which normally increases indirect bilirubin levels.
Bilirubin – Urine
Urine Test – A lab test to measure the amount of bilirubin in the urine.
Large amounts of bilirubin in the body can lead to jaundice.
Bilirubin 1 – Bilirubin Pathway
Bilirubin 2 – Bilirubin Metabolism & Diseases
Bilirubin & Urobilinogen: Definition & Symptoms
Bilirubin Metabolism Simplified