Bilirubin is a substance produced as a result of the breakdown of red blood cells. After red blood cells have completed their functions in the body, they are broken down and processed by the liver and mixed into bile. It is excreted from the body along with the bile. Elevated bilirubin levels may occur due to impaired liver function or extensive red blood cell breakdown.
If the liver is damaged, bilirubin can leak into the bloodstream and cause jaundice. A bilirubin test can help identify diseases affecting the liver.
How Is a Bilirubin Blood Test Performed?
A bilirubin blood test is a laboratory analysis of a blood sample. While this test is performed by healthcare professionals using a blood sample drawn from a vein in adults, it is performed using a blood sample taken from the heel in newborns. Healthcare professionals may ask the patient to avoid eating or drinking anything for 4 hours before the test or may provide different instructions. The healthcare professional will provide the patient with the necessary information regarding this.
What Causes High Bilirubin Levels?
A bilirubin level of 1.24 mg/dL or higher is referred to as elevated bilirubin. This condition is also known as hyperbilirubinemia. Depending on the underlying causes, the following conditions can lead to elevated bilirubin:
Gallstones: Gallstones can form as a result of the hardening of substances such as cholesterol or bilirubin in the gallbladder, which can block the passage of these substances from the gallbladder to the intestines. This, in turn, causes the bilirubin level in the body to rise.
Gilbert’s Syndrome: This is a genetic disorder that prevents the liver from properly processing bilirubin. This substance, which cannot be processed by the liver, accumulates in the blood, leading to hyperbilirubinemia
. Liver Dysfunction: A condition that impairs liver function can interfere with the processing of bilirubin, causing its levels in the blood to rise.
Viral Hepatitis: This condition typically results from inflammation of the liver caused by a viral infection. The liver cannot function properly, and the bilirubin level in the blood rises.
Bile Duct Obstruction: Inflammation in the bile ducts can cause blockages, preventing substances in the bile from being transported to the intestines. This also leads to an increase in bilirubin levels in the body.
Intrahepatic Cholestasis of Pregnancy: This is known to be a temporary condition occurring during the last three months of pregnancy. It causes the flow of bile in the liver to slow down or stop completely. Consequently, it becomes difficult to excrete bilirubin from the body, and its level in the body rises.
What Are the Symptoms of High Bilirubin Levels?
Symptoms of high bilirubin levels depend on the underlying cause of the condition and may vary from person to person. Common symptoms include the following:
- Abdominal pain or swelling,
- Shivering,
- Fever,
- Chest pain,
- Weakness,
- Dizziness,
- Nausea and vomiting,
- Dark urine.
What Causes Low Bilirubin Levels?
Factors that may temporarily cause low bilirubin levels include caffeine consumption, oxygen deficiency, and the use of pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or barbiturates. However, no specific disease has been identified as a cause of this condition.
It is not fully known whether low bilirubin levels are harmful to human health. With its antioxidant properties, bilirubin is thought to offer protection against many diseases, such as coronary artery disease, ulcerative colitis, stroke, and eye diseases.
What Are the Symptoms of Low Bilirubin?
Low bilirubin levels generally do not cause any symptoms in people. Low bilirubin levels may be detected during routine blood tests.