Biomarkers

Bilirubin

Bilirubin is an essential marker for assessing liver health. High levels may signal liver dysfunction or bile duct obstruction. Regular monitoring of bilirubin levels is crucial for early detection and management of conditions such as hepatitis or hemolytic anemia.

What is bilirubin?

Bilirubin is a yellow-orange pigment that is produced when the body breaks down aging or damaged red blood cells. This natural process occurs when red blood cells reach the end of their life cycle.

After production, bilirubin is carried through the bloodstream to the liver, where it is processed. It is then combined with bile, a digestive fluid, and excreted in the intestines. Bilirubin contributes to the digestion of fats and is eliminated from the body through the stool, to which it gives their characteristic color.

Bilirubin tests

Blood tests

  1. Total bilirubin : Measures the total amount of bilirubin in the blood, including direct (conjugated) and indirect (unconjugated) bilirubin.
  2. Direct Bilirubin (Conjugated) : Reflects bilirubin already transformed by the liver. High levels may indicate problems with bile excretion, such as bile duct obstruction or liver disease.
  3. Indirect Bilirubin (Unconjugated) : Reflects bilirubin before it is processed by the liver. High levels may suggest conditions such as hemolytic anemia.

Urine tests

Urine bilirubin tests are less common but useful for detecting liver disease or bile obstructions. The presence of bilirubin in the urine often indicates high levels in the blood.

Preparing for the Bilirubin Test

  • Fasting : Avoid eating or drinking (except water) for 4 hours prior to the test.
  • Medications : Tell your doctor about any medications you are taking, as some may influence the results.
  • Physical Activity : Avoid strenuous physical exertion prior to the test, as it may temporarily increase bilirubin levels.

Normal Blood Bilirubin Levels

  • Adults :
    • Total bilirubin: up to 1.2 mg/dL.
    • Direct bilirubin: Less than 0.3 mg/dL.
  • Children (<18 years old) :
    • Total bilirubin: up to 1 mg/dL.

In the urineBilirubin is not normally detected in the urine. If present, it often indicates a liver or bile problem.

Abnormal Bilirubin Levels

High levels

Causes :
  • Hepatic dysfunction : Cirrhosis, hepatitis, or other conditions that affect the liver's ability to process bilirubin.
  • Bile Duct Obstruction : Gallstones or tumors can block the excretion of bilirubin.
  • Accelerated destruction of red blood cells : Hemolytic anemia causes excessive bilirubin production.
Associated conditions :
  • Hepatitis : Inflammation of the liver that reduces its ability to process bilirubin.
  • Cirrhosis : Healing of the liver interfering with its normal functions.
  • Hemolytic anemia : Rapid destruction of red blood cells increasing bilirubin.

Low levels

Low bilirubin levels are less of a concern but may be linked to:

  • Medications : Some medications, such as barbiturates or caffeine, can reduce bilirubin production.
  • Genetic Factors : Some people naturally have lower bilirubin levels.

Symptoms of Abnormal Bilirubin Levels

Symptoms of Abnormal Bilirubin Levels

  • Jaundice (jaundice) : Yellowing of the skin and eyes.
  • Dark urine : Signal for the excretion of bilirubin in the urine.
  • Fatigue : Indication of liver dysfunction.
  • Discolored stools : Potential bilirubin excretion problem.

These symptoms, while subtle, may indicate underlying conditions and require medical evaluation.

Managing High Bilirubin Levels

Lifestyle Changes

  1. Feeding : Eat liver-friendly foods, such as green leafy vegetables, beets, and foods that are rich in antioxidants. Limit the consumption of alcohol, processed foods, and sugars.
  2. Hydration : Drink enough water to support detoxification processes.
  3. Toxin reduction : Minimize exposure to environmental toxins and avoid recreational drugs.

Medical treatments

  1. Medications : Prescribed to treat underlying conditions affecting bilirubin.
  2. Phototherapy : Used in newborns to break down bilirubin in the skin.
  3. Surgery : In case of bile duct obstruction, intervention may be required to remove the blockages.

When to See a Doctor?

A bilirubin test is often prescribed for symptoms related to the liver or bile ducts. In case of abnormal results, consult a general practitioner who can refer you to a specialist, such as a hepatologist, for appropriate treatment.