Bilirubin in Urine: What Does a Positive Result Mean?

Bilirubin in urine, called bilirubinuria, means a urine test has found a pigment that is not normally present there. It usually points clinicians towards the liver or the bile ducts, because the form of bilirubin that reaches urine builds up when bile cannot leave the liver normally. It is a signal to investigate, not a diagnosis by itself.

Bilirubin is a yellow substance made when old red blood cells are broken down. The liver processes it and sends it out in bile. MedlinePlus notes that bilirubin in urine can be an early sign of a liver condition and may appear before symptoms do.

This guide is for adults who have a urine result in front of them, often from a routine dipstick or urinalysis. It explains what the result can and cannot tell you, and how to prepare for the follow-up conversation.

If your skin or the whites of your eyes turn yellow, the NHS advises asking for an urgent GP appointment or contacting NHS 111, or the equivalent urgent service where you live. Yellowing can be harder to see on brown or black skin, so the whites of the eyes are often a better guide.

Healthdirect advises calling emergency services if jaundice comes with sudden symptoms such as fever, confusion and strong abdominal pain, or if you are vomiting blood. Jaundice during pregnancy should be raised with a doctor or midwife straight away.

• Yellow skin or yellow whites of the eyes
• Dark urine together with pale or clay-coloured stools
• Fever or strong abdominal pain together with yellowing
• Confusion, unusual drowsiness or vomiting blood
• Itching with any of the signs above

Bilirubin exists in two main forms. Unconjugated (indirect) bilirubin has not yet been processed by the liver. It does not dissolve in water, so the kidneys cannot filter it into urine.

Conjugated (direct) bilirubin has been processed by the liver and dissolves in water. A review in American Family Physician explains that this water-soluble form can be excreted in urine, and that finding it on a dipstick should prompt investigation for liver or bile duct disease.

This is why a urine result and a blood result can tell different stories. Someone can have a raised total bilirubin in the blood with no bilirubin in their urine, if the raised part is mainly the unconjugated form.

MedlinePlus lists several broad groups of causes for bilirubin in urine. Your clinician will narrow these down using your symptoms, examination, blood tests and sometimes a scan.

• Liver inflammation or damage, such as hepatitis or cirrhosis
• A blockage in the bile ducts, including gallstones that have moved into the ducts
• Narrowing or scarring of the bile ducts
• Tumours of the liver, gallbladder, pancreas or bile ducts, which are less common causes
• Some medicines that affect the liver

Gilbert's syndrome is a common inherited condition that causes mild, intermittent jaundice. Healthdirect groups it with causes that act before the liver has processed bilirubin, so the extra bilirubin is mainly the unconjugated form, which does not pass into urine. The NHS notes that Gilbert's syndrome does not usually cause darker urine, and that dark urine, pale stools or itchy skin are more likely to suggest jaundice from another cause.

So a positive urine bilirubin is not usually explained by Gilbert's syndrome alone. If you already have a Gilbert's diagnosis and your urine test is positive, it is reasonable to ask whether the new result changes the picture.

No. Dark urine has many causes. MedlinePlus describes clear dark-brown urine as a possible sign of a liver disorder, but notes that severe dehydration and muscle breakdown can also darken urine. Some vitamins, foods and medicines can turn urine dark yellow or orange.

Contact a clinician if dark-brown urine does not go away, if the colour is unexplained, or if it comes with pale stools or yellowing. The urine bilirubin test helps separate a bile-related cause from simple concentration.

Dipstick tests are screening tools. American Family Physician lists some medicines, such as phenazopyridine and chlorpromazine, as possible causes of false-positive results. Vitamin C, selenium and prolonged light exposure can cause false negatives, because bilirubin breaks down in light.

Because of this, a positive dipstick is usually followed by liver blood tests rather than a repeat urine test alone. Tell the clinician about all medicines and supplements you take. Do not stop a prescribed medicine to change a test result without advice.

MedlinePlus says an abnormal result often leads to a liver panel, a group of blood tests that measure liver enzymes, proteins and bilirubin. The blood bilirubin can be split into conjugated and unconjugated parts. Depending on the results and your symptoms, the clinician may also arrange imaging of the liver, gallbladder and bile ducts.

Reference ranges for blood tests differ between laboratories, so compare your numbers with the range printed on your own report. The overall pattern and trend matter more than a single value.

Bring the urine report and any blood results to the appointment. These questions can help you leave with a clear plan.

• Was this a dipstick result or a laboratory test, and does it need confirming?
• Which liver blood tests will be checked, and when will I get the results?
• Is my raised bilirubin mainly conjugated or unconjugated?
• Could any of my medicines or supplements affect the result?
• Do I need a scan of the liver and bile ducts?
• Which symptoms should make me seek help before the next appointment?

On SameCase, patients and verified doctors share de-identified cases. Reading how others with a positive urine bilirubin were assessed, which tests they had and what they asked can help you write a clearer list of questions. Similar cases cannot tell you what is causing your own result, and your care team remains the place for diagnosis and decisions.