What Is Gilbert Syndrome

Have you or someone close to you been recently diagnosed with Gilbert syndrome? Whilst the name may sound daunting and scary, this article will aim to cover all the burning questions you have in your head about this common disorder. 

Gilbert syndrome is a common genetically inherited condition that affects the liver and results in patients suffering from episodes of jaundice due to a build of bilirubin in the blood. 

This article will aim to discuss all the different factors surrounding Gilbert syndrome such as risk factors, diagnosis and treatment plans as well as cover frequently asked questions that many have been debating over this condition. 


Gilbert syndrome is an inherited disease affecting the liver. It is characterised by hepatic dysfunction leading to an overproduction of bilirubin (yellow pigment produced by red blood cell breakdown) and causing jaundice. Due to this characteristic, symptoms such as yellowing of the skin and eyes are most notable with this disease whilst in others there are no symptoms at all. Gilbert syndrome is not known to be harmful nor cause long-lasting problems, therefore treatment and management of the disease are often not necessary1.

Causes of gilbert syndrome

Gilbert syndrome is a genetic condition. In the normal lifespan of red blood cells, at the end of around 120, the red pigment that is responsible for carrying oxygen on these cells (haemoglobin), breaks down into bilirubin. In healthy people, the UGT1A1 gene is responsible for creating liver enzymes that break down bilirubin in the liver. In people who have Gilbert syndrome, two copies of the mutated gene are inherited. This mutated gene will only create around 30% of the enzymes required for this process. Due to the lack of enzymes, the blood will begin to contain excess amounts of bilirubin. The buildup of bilirubin in the blood is responsible for the characteristic symptoms of Gilbert syndrome such as yellowing of the eyes and skin (jaundice).1,2 

Apart from inheriting a modified version of the gene, there are no other known causes of Gilbert syndrome. No environmental or lifestyle factors or previous history of other liver conditions have been associated with developing Gilbert syndrome.2

Signs and symptoms of gilbert syndrome

Only around 1 in 3 people with Gilbert syndrome experience symptoms, with many people not experiencing anything at all. 

The most common symptom of Gilbert syndrome is jaundice, which is often mild and not harmful.3 

However, some people who experience jaundice may also have other symptoms such as: 

  • Loss of appetite 
  • Fatigue 
  • Flu-like symptoms
  • Dark coloured urine
  • Clay coloured stool 
  • Dizziness 
  • Gastrointestinal issues 
  • Difficulties concentrating

Management and treatment for gilbert syndrome

Currently, there is no specific treatment plan for people with Gilbert syndrome. This is because the condition generally does not cause harm or any long-term side effects. If a patient is aware that they have the disease or are a carrier then it should be noted to their healthcare provider, as increased levels of bilirubin can inhibit certain drugs from being broken down effectively by the body. 

Certain drugs that should be avoided in patients with Gilbert syndrome, where possible include: 

  • Gemfibrozil
  • Nilotinib
  • Atazanavir and indinavir
  • Statins (drugs that lower cholesterol) 
  • Irinotecan

At present, many people with Gilbert syndrome are recommended to live a healthy lifestyle by having a well-balanced diet and plenty of exercise as this has been shown to improve stress levels and therefore reduce the risk of any flare-ups. High consumption of alcohol in their diet has been shown to make the condition worse.4 

Diagnosis of Gilbert syndrome

Since Gilbert syndrome is a genetically inherited condition, it is already present at birth. Diagnosis of this condition, however, often does not take place until the teen years or early adulthood particularly if the patient is asymptomatic, as it would only show up on a routine blood test. 

Gilbert syndrome can be diagnosed by using blood tests to determine the levels of bilirubin in the blood. In addition to this, a liver function test may also be requested to assess the level of proteins and enzymes in the liver and determine the capacity at which it is functioning. 

Other less common factors that may be tested in blood panels include: 

Additionally, other further tests that may be requested include: 

  • Plasma unconjugated bilirubin response to fasting
  • Plasma unconjugated bilirubin response to nicotinic acid
  • UGT1A1 genotyping
  • Liver biopsy (take a sample of liver tissue)

Furthermore, genetic testing may also be necessary to accurately diagnose Gilbert syndrome. 

If test results come back conclusive with high levels of bilirubin but the liver function is otherwise not compromised, the diagnosis of Gilbert syndrome is usually made.5 

Risk factors

Gilbert syndrome is common, however, it is not always easy to accurately determine the number of people suffering from it due to the lack of obvious symptoms and diagnosis usually occurring in patients when they are older. 

Several risk factors are associated with developing Gilbert syndrome. These include: 

  • Being assigned male at birth (AMAB) 
  • Having type 1 diabetes 
  • If both parents are a carrier of the modified gene 6


Gilbert syndrome is a lifelong condition that does not require a treatment plan. It is non-threatening and has shown no increased signs of liver disease. Although episodes of jaundice are common, these are often unproblematic, short-lived, and will resolve on their own.7 


Can I prevent gilbert syndrome?

Gilbert syndrome is a genetically inherited disorder therefore, prevention of the disease is not possible. 

However, patients who are living with this condition can generally avoid any severe side effects or complications as a result of this disease that would otherwise prevent them from having a normal life.8 

What is bilirubin?

Bilirubin is a compound that is found in small amounts in the blood. It is the result of the breakdown of haemoglobin, which is a compound found in red blood cells that is responsible for carrying oxygen in the blood. Haemoglobin is converted to bilirubin in the liver to a more soluble form that can be excreted through the body.8 

How common is gilbert syndrome?

In the UK, around 1 in 20 people are affected by Gilbert syndrome. This statistic however is incredibly difficult to monitor as many people who have the condition do not always display clear symptoms and are often undiagnosed until adulthood. Therefore, it is thought that this number is higher and that the disorder is more common than the data we are currently provided with.9 

When should I see a doctor?

If you are suffering from the common symptom of Gilbert syndrome which is jaundice for the first time, make an appointment with your general practitioner (GP). Although this symptom is mild in patients with Gilbert syndrome, it can sometimes be associated with other more serious liver conditions such as hepatitis C or cirrhosis of the liver (scarring of the liver)9.


To conclude, Gilbert syndrome is a genetically inherited condition that is caused by inheriting two copies of a mutated gene that are responsible for the breakdown of bilirubin in the liver. The symptoms are characterised by episodes of jaundice that are mild and usually resolve on their own. Many patients may not even experience symptoms. Simple blood and liver function tests can be used for diagnosis, however, this usually does not occur in patients until they are older, despite it being a genetic condition present from birth. 

It is a common, non-threatening condition that many people live with long-term. No treatment or medications are required to manage the disease, with a healthy diet and exercise you can lead a very normal and unproblematic life with this condition. 


  1. Watson KJR, Gollan JL. Gilbert’s syndrome. Baillière’s Clinical Gastroenterology [Internet]. 1989 [cited 2023 May 4]; 3(2):337–55. Available from: https://www.sciencedirect.com/science/article/pii/0950352889900043.
  2. Burchell B, Hume R. Molecular genetic basis of Gilbert’s syndrome. J Gastroenterol Hepatol [Internet]. 1999 [cited 2023 May 4]; 14(10):960–6. Available from: http://doi.wiley.com/10.1046/j.1440-1746.1999.01984.x.
  3. Maruo Y, Nakahara S, Yanagi T, Nomura A, Mimura Y, Matsui K, et al. Genotype of UGT1A1 and phenotype correlation between Crigler-Najjar syndrome type II and Gilbert syndrome: Crigler-Najjar and Gilbert syndromes. Journal of Gastroenterology and Hepatology [Internet]. 2016 [cited 2023 May 4]; 31(2):403–8. Available from: https://onlinelibrary.wiley.com/doi/10.1111/jgh.13071.
  4. Thoguluva Chandrasekar V, Faust TW, John S. Gilbert Syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 May 4]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK470200/.
  5. Committee on Diagnostic Error in Health Care, Board on Health Care Services, Institute of Medicine, The National Academies of Sciences, Engineering, and Medicine. Improving Diagnosis in Health Care [Internet]. Washington, D.C.: National Academies Press; 2015 [cited 2023 May 4]. Available from: http://www.nap.edu/catalog/21794.
  6. Kamal S, Abdelhakam S, Ghoraba D, Massoud Y, Aziz KA, Hassan H, et al. The frequency, clinical course, and health related quality of life in adults with Gilbert’s syndrome: a longitudinal study. BMC Gastroenterology [Internet]. 2019 [cited 2023 May 4]; 19(1):22. Available from: https://doi.org/10.1186/s12876-019-0931-2.
  7. Gilbert’s Syndrome - an overview | ScienceDirect Topics [Internet]. [cited 2023 May 4]. Available from: https://www.sciencedirect.com/topics/medicine-and-dentistry/gilberts-syndrome.
  8. Gilbert Syndrome - Symptoms, Causes, Treatment | NORD [Internet]. [cited 2023 May 4]. Available from: https://rarediseases.org/rare-diseases/gilbert-syndrome/.
  9. Gilbert’s syndrome. nhs.uk [Internet]. 2017 [cited 2023 May 4]. Available from: https://www.nhs.uk/conditions/gilberts-syndrome/.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Sarah Nadiri

Masters in Cancer, MSc University College London, London

Sarah is a registered biomedical scientist with a specialty in cancer research studies. She has five years experience working in various research facilities such as the Cancer Institute and The Francis Crick Institute. Additionally she has experience working in clinics, in various hospital labs around London and various intermediary care roles within the NHS. She joined Klarity in February and is currently contributing as a medical writer.

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