ConditionDigestive system
Gilbert Syndrome
Gilbert syndrome is a common, harmless inherited condition in which the liver processes bilirubin, a yellow pigment from the normal breakdown of red blood cells, more slowly than usual. Bilirubin levels run slightly high, and the whites of the eyes or skin can turn faintly yellow at times, especially during fasting, illness, stress or dehydration. It affects around 3% to 7% of people and is often found by chance on a blood test. It needs no treatment and does not damage the liver.
Also called: Gilbert's syndrome, Gilbert disease, constitutional hepatic dysfunction, familial nonhemolytic jaundice, Meulengracht disease
At a glance
- What it is
- Reduced activity of the liver enzyme that processes bilirubin (UGT1A1), from an inherited gene variant.
- How common
- About 3% to 7% of people; often noticed after puberty.
- Symptoms
- Usually none; mild, intermittent yellowing of the eyes or skin.
- Triggers
- Fasting, illness, stress, dehydration, hard exercise, lack of sleep, menstruation.
- Diagnosis
- Mildly raised unconjugated bilirubin with otherwise normal liver tests and blood count.
- Treatment
- None needed; be aware of certain medicine interactions.
When to get help
See a doctor within a day or two
- Yellow skin or eyes with dark urine, pale stools, itching, fever or abdominal pain (suggests a different liver or bile duct problem)
- Yellowing with tiredness, breathlessness and pale skin (possible hemolytic anemia)
- Jaundice in a newborn that appears in the first 24 hours or is spreading
Book a routine appointment
- First episode of mild yellowing of the eyes, for a blood test to confirm the cause
- Raised bilirubin found on a routine test, especially if other liver tests are abnormal
- Starting chemotherapy or HIV medicines with known Gilbert syndrome (tell your doctor)
What happens in Gilbert syndrome
When old red blood cells are broken down, bilirubin is released. The liver attaches a sugar molecule to it (a process called conjugation, performed by the enzyme UGT1A1) so it can be excreted in bile. In Gilbert syndrome, a change in the UGT1A1 gene reduces the enzyme's activity to around a third of normal. Unconjugated (indirect) bilirubin builds up a little in the blood.
The liver is otherwise completely healthy. Bilirubin levels usually stay below about 3 mg/dL (51 µmol/L), compared with a typical upper normal limit of around 1.2 mg/dL (20 µmol/L).
Inheritance
Most people with Gilbert syndrome have inherited the variant from both parents (autosomal recessive). It is diagnosed more often in males, possibly because hormones affect bilirubin levels.
Symptoms
Most people have no symptoms at all. When bilirubin rises, you may notice:
- mild yellowing of the whites of the eyes (yellow eyes) or skin
- episodes that last a few days and then fade
Some people report tiredness, nausea, abdominal discomfort or difficulty concentrating during episodes. Studies have not clearly shown that Gilbert syndrome causes these symptoms; they may be related to the illness or fasting that triggered the episode.
Triggers
- fasting or skipping meals, including very low-calorie diets
- illness, such as colds and flu
- dehydration
- emotional or physical stress
- strenuous exercise
- lack of sleep
- menstruation
- alcohol
Diagnosis
Gilbert syndrome is usually diagnosed from blood tests showing:
- mildly raised total bilirubin, mostly unconjugated
- normal liver enzymes (ALT, AST, alkaline phosphatase)
- a normal blood count and no signs of red cell breakdown (hemolysis)
- the pattern persisting on repeat testing
A genetic test for the UGT1A1 variant is available but is rarely needed. A liver biopsy is not necessary.
Conditions doctors rule out
| Condition | How it differs |
|---|---|
| Hemolytic anemia | Raised bilirubin with anemia and signs of red cell breakdown |
| Crigler-Najjar syndrome | Much higher bilirubin, from very low or absent enzyme activity, usually from birth |
| Hepatitis and other liver disease | Abnormal liver enzymes, often conjugated bilirubin |
| Bile duct blockage | Conjugated bilirubin, dark urine, pale stools, itching |
Treatment
No treatment is needed. Gilbert syndrome does not progress, does not cause liver damage and does not shorten life expectancy.
Practical tips
- Eat regular meals and avoid prolonged fasting if you notice yellowing.
- Stay well hydrated, especially during illness and exercise.
- Get enough sleep and manage stress.
- Tell doctors you have Gilbert syndrome, so a mildly raised bilirubin is not over-investigated and medicines are chosen carefully.
Medicines and Gilbert syndrome
Because UGT1A1 also processes some drugs, people with Gilbert syndrome may be more sensitive to:
- irinotecan (a chemotherapy drug): higher risk of low white cell counts and diarrhea; doses may be adjusted
- atazanavir and some other HIV protease inhibitors: more likely to raise bilirubin and cause yellowing
- some other medicines, according to their prescribing information
Acetaminophen (paracetamol) at normal doses is generally considered safe, though some guidance advises care with high doses.
Outlook
Gilbert syndrome is a lifelong but benign trait. Some research suggests mildly higher bilirubin may even be associated with a lower risk of heart disease, possibly because bilirubin is an antioxidant.
Frequently asked questions
Is Gilbert syndrome serious?
No. Gilbert syndrome is a harmless, inherited trait that causes mildly raised bilirubin. It does not damage the liver, does not need treatment and does not affect life expectancy. The main practical point is telling doctors about it, for medicine choices and test interpretation.
What triggers Gilbert syndrome symptoms?
Fasting or skipping meals, illness, dehydration, stress, strenuous exercise, lack of sleep, menstruation and alcohol can raise bilirubin levels and cause temporary yellowing of the eyes or skin.
Can Gilbert syndrome cause fatigue?
Many people report tiredness, but studies have not proven that Gilbert syndrome itself causes fatigue. Tiredness may come from the illness, fasting or stress that also triggers higher bilirubin. If fatigue is persistent, other causes should be checked.
Is there a diet for Gilbert syndrome?
No special diet is needed. Eating regular meals, avoiding long periods of fasting, staying hydrated and limiting alcohol can help prevent episodes of yellowing.
Can I drink alcohol with Gilbert syndrome?
Gilbert syndrome does not make the liver more vulnerable to alcohol damage, but alcohol can temporarily raise bilirubin. Following general guidelines for moderate drinking is reasonable.
Sources
This guide was written from current patient and clinical guidance, including:
- MedlinePlus Genetics: Gilbert syndrome
- NHS: Gilbert's syndrome
- American College of Gastroenterology: Clinical guideline, evaluation of abnormal liver chemistries (2017)
- NIH Genetic and Rare Diseases Information Center: Gilbert syndrome
- British Liver Trust: Gilbert's syndrome