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what causes bilirubin to be high

High bilirubin (hyperbilirubinemia) usually means either your body is making too much bilirubin, your liver can’t process it properly, or bile can’t drain out of the liver and gallbladder.

What causes bilirubin to be high?

Bilirubin is a yellow pigment made when red blood cells break down. It travels to the liver, gets processed (conjugated), then leaves the body in bile through the bile ducts into the intestine. When any part of this pathway is disrupted, levels in the blood can rise and cause jaundice (yellowing of eyes/skin).

Below is a breakdown by where the problem occurs.

1. Before the liver: too much production

Here the liver is normal, but it’s overwhelmed by excess bilirubin production, usually from increased breakdown of red blood cells. Common “pre‑hepatic” causes:

  • Hemolytic anemia (immune or non‑immune destruction of red blood cells).
  • Genetic blood disorders (sickle cell disease, thalassemia, hereditary spherocytosis).
  • Large bruises or internal bleeding being reabsorbed.
  • Some infections that destroy red blood cells (for example, malaria).
  • Certain enzyme deficiencies affecting red blood cell stability.

These usually cause high unconjugated (indirect) bilirubin.

2. In the liver: processing problem

Here the liver cells are inflamed, injured, or genetically unable to handle bilirubin properly. Liver (hepatic) causes:

  • Viral hepatitis (such as hepatitis A, B, C).
  • Alcohol‑related liver disease (fatty liver, alcoholic hepatitis, cirrhosis).
  • Non‑alcoholic fatty liver disease.
  • Drug or toxin‑related liver injury (for example, overdose of acetaminophen, certain antibiotics or anti‑seizure meds).
  • Autoimmune hepatitis (immune system attacks liver cells).
  • Cirrhosis from any cause (chronic scarring of the liver).
  • Liver tumors or metastases (cancer that starts in or spreads to the liver).

These conditions often raise conjugated (direct) or mixed bilirubin and may come with abnormal liver enzymes.

3. After the liver: bile flow blocked

Here the liver can form bilirubin, but bile cannot drain properly through the bile ducts. Post‑hepatic / obstructive causes:

  • Gallstones blocking the common bile duct.
  • Gallbladder disease (cholecystitis, gallbladder polyps, strictures).
  • Tumors compressing or invading bile ducts (pancreatic cancer, bile duct cancer, sometimes liver or colon cancer).
  • Pancreatitis (inflammation of the pancreas causing swelling around the bile duct).
  • Scarring or narrowing of bile ducts after surgery or chronic inflammation.

These typically cause high conjugated bilirubin and pale stools, dark urine, and itching.

4. Genetic and benign conditions

Some people have chronically high bilirubin without serious liver damage. Key inherited conditions:

  • Gilbert syndrome
    • Very common, usually mild.
    • Due to reduced activity of the enzyme that conjugates bilirubin.
    • Bilirubin may rise with fasting, stress, illness, or overexertion.
  • Other rare enzyme disorders (Crigler–Najjar, Dubin–Johnson, Rotor syndromes)
    • Typically diagnosed in childhood or young adulthood.
    • Can cause persistent high bilirubin, sometimes more severe.

Gilbert syndrome mainly raises unconjugated bilirubin but is typically considered harmless.

5. Other factors that can push bilirubin up

These don’t always cause disease by themselves but can worsen an underlying tendency to high bilirubin.

  • Dehydration.
  • Not eating enough or prolonged fasting.
  • Severe physical stress, illness, or infection.
  • Certain medications that affect liver enzymes or bile flow.
  • Heavy, long‑term alcohol use.

In people with Gilbert syndrome or mild liver disease, these triggers can temporarily raise levels and cause visible jaundice.

6. When high bilirubin is seen in tests

A “high” bilirubin is usually anything above roughly 1.2 mg/dL in adults, though exact cut‑offs vary by lab. Jaundice often becomes visible when bilirubin is above about 3 mg/dL.

Doctors usually look at:

  • Total bilirubin, direct (conjugated) bilirubin, and indirect (unconjugated) bilirubin.
  • Liver enzymes (ALT, AST, ALP, GGT).
  • Blood counts and hemolysis markers (hemoglobin, reticulocyte count, LDH, haptoglobin).
  • Ultrasound or other imaging if obstruction is suspected.

The pattern of results helps them decide whether the cause is pre‑hepatic, hepatic, or post‑hepatic.

7. What this means for you (not medical advice)

If your bilirubin is high, the cause can range from benign (like Gilbert syndrome) to serious (like hepatitis, cirrhosis, or bile duct blockage).

Get urgent medical attention if you notice:

  • Yellowing of eyes or skin appearing suddenly.
  • Severe abdominal pain (especially upper right side), fever, or vomiting.
  • Very dark urine, pale or clay‑colored stools, or intense itching.
  • Confusion, extreme fatigue, or easy bruising.

Only a clinician who knows your history, medications, alcohol use, and blood test results can identify the exact cause and decide on treatment.

Information gathered from public forums or data available on the internet and portrayed here.