Urobilinogen in the urine is the result of bilirubin breakdown, which is metabolized in the gut and partially excreted by the kidneys. Its presence in urine can help your doctor assess liver function and red blood cell functioning, with abnormal levels possibly being a sign of liver disease, hemolysis, or bile duct obstruction.
The normal level of urobilinogen in the urine is under 1.0 mg/dL. Levels that are above 1.0 mg/dL may be a sign of liver problems, hemolytic anemia or biliary obstruction.
You should follow-up with your doctor if you have high levels of urobilinogen in your urine, as a more thorough assessment is required to identify a cause and initiate treatment as necessary.
What is urobilinogen in urine?
Urobilinogen is a colorless compound formed in the intestines when gut bacteria break down bilirubin. This process mainly involves bacterial species like Clostridium and Bacteroides, which convert bilirubin into urobilinogen through specific enzymes .
A portion of urobilinogen is reabsorbed into the bloodstream and recycled by the liver, while small amounts are eliminated in urine. Because of this, its presence in urine is considered an important indicator of liver and red blood cell health.
Normal urobilinogen levels
Normal urobilinogen levels in urine are usually between 0.1 and 1.0 mg/dL, although some laboratories may accept up to 1.8 mg/dL as normal .
Levels above 2.0 mg/dL are considered abnormal and generally indicate the need for further testing. Small, trace amounts are considered normal and typically do not require investigation.
High urobilinogen in urine: causes & symptoms
High levels of urobilinogen in urine can be linked to several health problems, particularly those involving the liver or red blood cells. In these cases, urobilinogen levels rise because bilirubin production or processing is impaired.
1. Liver disease
Some liver diseases, like cirrhosis, hepatitis, or liver cancer, can increase the amount of bilirubin, leading to high levels of urobilinogen in the urine. The presence of this breakdown product can occur with liver problems, even before more obvious symptoms start to emerge.
Therefore, if high levels of urobilinogen are noted in the urine, the doctor may also order other blood tests, like a complete blood count and liver enzyme tests.
2. Blood cell abnormalities
Some conditions cause the body to produce antibodies that attack red blood cells, resulting in their destruction. As a result, bilirubin levels increase in the blood, which can be detected in a blood test or through high levels of urobilinogen in the urine.
Hemolytic anemia is also associated with increased bilirubin levels, as well as splenomegaly. The spleen helps to filter the blood and remove old red blood cells, and when inflamed, it may cause increased bilirubin.
3. Biliary disease
Some conditions, like cholestasis (bile duct obstruction) or cholangitis (inflammation of the bile ducts), can lead to increased urobilinogen in the urine. These can also cause elevated bilirubin and liver enzyme levels in the blood.
Other possible causes
Systemic conditions such as congestive heart failure, malaria, or lead poisoning can also result in increased urobilinogen in urine.
Main symptoms
Urobilinogen in the urine itself does not cause symptoms, but it may be the result of another health condition, which may present with symptoms like:
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Dark urine
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Fatigue
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Changes in skin color
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Nausea and abdominal pain (especially if caused by liver disease)
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Rapid heart rate or shortness of breath (especially if caused by anemia)
It is important for your doctor to carefully assess these symptoms alongside other urine and blood test results to diagnose the underlying cause.
Low urobilinogen in urine: what it means
Low or absent urobilinogen in urine may indicate that bilirubin is not reaching the intestines or that bacteria responsible for its conversion are reduced. This can happen with complete bile duct obstruction, advanced liver disease, or following antibiotic use that alters gut bacteria.
Congenital enzyme deficiencies that affect bilirubin metabolism can also cause persistently low levels. Symptoms related to these conditions may include clay-colored stools, jaundice, itching, and upper abdominal pain.
How the test is done
Urobilinogen is usually tested as part of a routine urinalysis with a dipstick. The test works through a chemical reaction that produces a pink color if urobilinogen is present. To perform the test:
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A fresh midstream urine sample is collected in a sterile container.
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A dipstick strip is fully immersed in the sample for a few seconds.
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The strip is removed, and excess urine is shaken off.
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After 60 to 120 seconds, the result is read by comparing the color change with the reference scale provided by the manufacturer.
Some medications and foods may affect the accuracy of results, and abnormal findings should always be confirmed with additional tests.
When to see a doctor
Medical consultation is recommended when urobilinogen levels are outside the normal range, particularly if symptoms are present. High levels above 2.0 mg/dL usually require testing for liver disease, hemolytic disorders, or bile duct problems.
Very low or absent levels with jaundice or abdominal pain may suggest bile duct obstruction that needs urgent evaluation. Warning signs that should prompt immediate medical attention include jaundice, dark urine, clay-colored stools, fatigue, and unexplained weight loss.