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Bilirubin is one of the key substances measured on a liver function blood test. It is a waste product created during the liver's breakdown of spent red blood cells (hemoglobin). Red blood cells can become damaged, and the body must remove them. Even healthy red blood cells eventually wear out after about 120 days, and the body clears them.¹
High bilirubin in adults generally indicates liver damage or that the liver has lost its ability to excrete or eliminate substances. However, other factors (such as taking certain medications) can induce high bilirubin, also known as hyperbilirubinemia.
Cirrhosis is a condition of the liver. It is progressive liver damage that eventually becomes irreversible. It is not a single, simple condition but a final result of any form of chronic liver damage.
While nearly any form of liver damage can cause cirrhosis, the most common causes in the US population are hepatitis C, non-alcoholic fatty liver disease, and excess alcohol consumption.² While cirrhosis's causes vary, all cases result in similar issues and structural changes in the liver.
For instance, cirrhosis involves the destruction and breakdown of liver tissue. The damaged tissue is replaced by non-functional fibrous tissue (scarring). It can also damage the liver's blood supply and cause the formation of nodules.
Cirrhosis is underdiagnosed. According to a study published in the American Family Physician, only 30% of people with cirrhosis have symptoms.³
However, as liver function worsens, affected individuals will experience signs like jaundice, bleeding, and fluid buildup in the abdomen.
The progression of cirrhosis depends on getting a diagnosis, treatment, and any other medical conditions that might be a factor.
People with cirrhosis often (but not always) have elevated bilirubin levels in blood tests.⁴
While most people with cirrhosis do not have symptoms, when they do develop, they include:
Extreme tiredness and weakness
Abdominal pain or discomfort
Signs of disease progression and liver health deterioration (clinically known as decompensation) include:
The buildup of fluid around the abdomen (ascites)
Hepatic fetor (chronic bad breath)
Jaundice (yellowing of the eyes and skin)
Both bilirubin types are measured in a blood test: conjugated and unconjugated bilirubin.
Total bilirubin is also calculated.
When red blood cells are broken down, unconjugated bilirubin is formed.
It is then conjugated (unified) in the liver forming conjugated bilirubin (also known as direct bilirubin) and secreted in bile.
Conjugation depends on the liver's enzymatic capability (adequate function).
High unconjugated bilirubin levels are usually secondary to either increased bilirubin production, disorders that destroy red blood cells, or decreased bilirubin uptake.
Conditions that can present with high unconjugated bilirubin levels often include
Hemolytic anemia which destroys red blood cells faster than the remnants can be processed
Congestive heart failure in which the heart can’t provide sufficient blood flow to the liver
Genetic conditions that decrease the liver’s conjugative ability, such as Gilbert’s or Crigler-Najjar syndrome
High conjugated bilirubin indicates that the bilirubin has made it into the liver and is conjugated. The issue is typically due to the liver being unable to secrete bilirubin into the bile ducts or an obstruction of the biliary flow.
Here is an overview of normal ranges for bilirubin levels.⁵
Bilirubin values above these ranges may indicate cirrhosis or another liver problem. It depends on which values are elevated and the results of other tests. However, some people with cirrhosis will have completely normal bilirubin values. So, normal bilirubin values do not rule out cirrhosis.
People with different underlying causes of cirrhosis may have different bilirubin levels.⁶ For instance, some conditions may affect conjugated bilirubin more than unconjugated bilirubin.
No fixed bilirubin level can diagnose cirrhosis because many people with cirrhosis will not have raised bilirubin.
Having raised bilirubin is also known as jaundice, and there can be numerous causes for it.
Additionally, many other conditions—separate from or associated with cirrhosis—can cause elevated bilirubin levels.
The following conditions cause an increase in unconjugated bilirubin by itself:
Gilbert's Syndrome (a genetic condition affecting the liver's processing of bilirubin)
Hemolysis (abnormal destruction of red blood cells)
Additionally, these factors, among others, can increase conjugated bilirubin
Excessive alcohol intake
Having infectious hepatitis (such as hepatitis C)
Taking certain prescription drugs⁷
When one drug affects the activity of another (drug-drug interactions)
Total bilirubin levels are a sum of conjugated and unconjugated bilirubin, so any of the above conditions can affect total bilirubin.
Improving liver function and treating underlying conditions is the best way to reduce bilirubin levels. Your doctor will be able to provide specific guidance on your situation. Jaundice as a symptom itself does not warrant treatment in adults. However, associated itching can be relieved with medications such as cholestyramine.
Bilirubin is one of the main waste products cleared by the liver. A blood test determines bilirubin levels, and elevated levels may indicate issues with liver function.
Cirrhosis is a disease of liver function. It has many causes and can result in high bilirubin levels. Many people with cirrhosis do not have any symptoms or bilirubin elevation.
In those with cirrhosis, elevated bilirubin usually indicates either reduced bilirubin elimination or high production and not enough elimination.
Elevated bilirubin levels are also seen in a variety of other health conditions. If you have symptoms of cirrhosis or have been diagnosed, it is important to talk to your doctor. They can provide specific guidance, including helping reduce bilirubin levels.
Bilirubin | Medscape