Gilbert Syndrome

What is Gilbert Syndrome?

Gilbert (pronounced zheel-BAYR) syndrome is a common, inherited, benign liver disorder. It isn’t a disease but a normal variant in which individuals have mildly elevated bilirubin concentrations in their blood due to the liver’s inability to properly process bilirubin.

Bilirubin, a yellowish pigment, is a substance produced by the breakdown of old red blood cells and hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the rest of the body. Normally, bilirubin is removed from the body through the digestive system (stool) as part of the bile from the liver. The amount of bilirubin in a person’s blood is usually very low.

Gilbert Syndrome is also known as constitutional hepatic dysfunction, benign unconjugated bilirubinemia and familial nonhemolytic jaundice.


People are born with Gilbert Syndrome which is caused by an abnormal but common gene that is inherited from one’s parents. Many people carry one copy of this abnormal gene. If two people who carry one copy of the defective gene have a child, the defective gene may get passed along causing Gilbert Syndrome. The gene normally controls an enzyme that helps break down bilirubin in the liver. Rather than being excreted from the body through elimination (stool), the defective gene causes a build up of bilirubin in the blood thereby causing the syndrome.

Who is at Risk?

Since it’s genetic, having parents who both carry the defective gene that causes the syndrome increases the likelihood of having the disorder. Occurring predominantly in men, with a male-to-female ratio ranging from 2-7:1, it occurs in persons of all races and is not specific to any particular ethnic group. The rate of Gilbert Syndrome in the United States is 3-7% of the population.


Most people don’t have signs or symptoms, so it can go undiagnosed for many years. There are other factors that may cause the elevation of bilirubin which worsens Gilbert Syndrome such as:

  • Fasting or skipping meals
  • Stress
  • Illness or viral infection
  • Menstruating
  • Dehydration
  • Strenuous exercise

Other than mild, intermittent jaundice which corrects itself, patients may report vague abdominal discomfort and general fatigue for which no cause is found. These episodes resolve spontaneously, and no treatment is required, except supportive care.

How is it Diagnosed?

Gilbert Syndrome is generally asymptomatic and is usually inadvertently discovered when blood tests performed for other reasons reveal an elevated bilirubin level. Some patients will seek medical attention because of jaundice (yellowing of the eyes and skin), especially while suffering from an unrelated illness. Generally, the inherited condition is diagnosed in adults or older children (around puberty).

Blood tests may be recommended to rule out other conditions, such as liver problems. Common blood tests include:

Repeated, costly investigations and extensive evaluations are not usually justified in establishing a diagnosis.


Because it’s not a disease, no treatment is required. Bilirubin levels may fluctuate over time and occasionally jaundice may occur but it usually goes away on its own and doesn’t require medical intervention. Sometimes phenobarbital, a drug that will decrease bilirubin concentration, is prescribed to lower extremely high bilirubin levels and reduce signs of jaundice.

To help keep bilirubin levels under control and avoid bouts of jaundice, individuals should try to manage stress and avoid strict, low calorie diets by eating healthy meals which include plenty of fruits and vegetables. Fasting or skipping meals is inadvisable as well. Because Gilbert Syndrome affects the way medicine is metabolized by the body, it is also important to advise all doctors that one has the disorder to prevent worsening of side effects from the drugs.

Long Term Prognosis

Gilbert Syndrome has an excellent prognosis, as individuals with the disorder can lead a normal lifestyle and have a normal lifespan. Studies have reported excellent results in patients undergoing liver donor transplantation from donors with Gilbert Syndrome.

This information is for educational purposes only and should not be used in any other manner. This information is not intended to substitute for informed medical advice. You should not use this information to diagnose or treat a health problem or disease without consulting with a qualified health care provider.

About the Author

Stephen Holt, MD, PhD, FACP

Stephen Holt, M.D. is a Distinguished Professor of Medicine NYCPM (Emerite) and a medical practitioner in New York State. He has published many peer-review papers in medicine and he is a best-selling author with more than twenty books in national and international distribution. He has received many awards for teaching and research. Dr. Holt is a frequent lecturer at scientific meetings and healthcare facilities throughout the world. He is a best selling author and the founder of the Holt Institute of Medicine.

American Liver Foundation "Gilbert Syndrome" Retrieved March 30, 2011 "Gilbert Syndrome" Retrieved March 30, 2011

Mayo Clinic "Gilbert’s Syndrome" Retrieved March 30, 2011

U.S. National Library of Medicine NIH National Institutes of Health "Gilbert’s Disease" Retrieved March 30, 2011

Worman, M.D. Howard J. The Liver Disorders and Hepatitis Sourcebook. McGraw-Hill, 2006

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