What is Gilbert’s syndrome?
Gilbert’s syndrome (also called Gilbert’s disease) is a common inherited liver condition. People who have it carry a change in the UGT1A1 gene, which means a liver enzyme works at roughly 30 percent of its usual capacity. That enzyme’s job is to prepare bilirubin, a yellow pigment made when old red blood cells break down, so the body can remove it.
Because bilirubin is cleared more slowly, levels in the blood run slightly higher than average and rise and fall over time. They tend to climb when the body is under stress, for example during fasting, dehydration, illness, heavy exercise or menstruation. When they climb far enough, the skin and the whites of the eyes can look mildly yellow (jaundice).
Gilbert’s syndrome does not damage the liver, does not progress into liver disease, and does not shorten life expectancy. An estimated 3 to 7 percent of people in the United States have it, and many only find out when a routine blood test shows a raised bilirubin level.
Is Gilbert’s syndrome life threatening?
No. Gilbert’s syndrome is not life threatening and does not damage the liver or shorten life expectancy. It usually causes only mild, temporary increases in bilirubin. However, new, severe or persistent jaundice should be checked by a clinician because it may have another cause, especially if it occurs with dark urine, pale stools, abdominal pain, fever or vomiting.
Key terms to know
- Bilirubin
- An orange-yellow pigment produced when old red blood cells are broken down. The liver processes it so it can leave the body in bile and stool.
- Unconjugated (indirect) bilirubin
- Bilirubin that has not yet been processed by the liver. This is the type that is raised in Gilbert’s syndrome.
- Conjugated (direct) bilirubin
- Bilirubin that the liver has processed and made water-soluble. Raised levels point to a liver or bile duct problem rather than Gilbert’s syndrome.
- Jaundice
- Yellowing of the skin and the whites of the eyes caused by too much bilirubin in the blood. Also called icterus.
- UGT1A1
- The gene that makes the enzyme (bilirubin-UGT) responsible for processing bilirubin. A change in this gene causes Gilbert’s syndrome.
- Hyperbilirubinemia
- The medical term for a higher-than-normal level of bilirubin in the blood.
- Liver function tests (LFTs)
- A group of blood tests, including bilirubin, ALT and AST, that show how well the liver is working. In Gilbert’s syndrome, the other liver tests are normal.
- Hemolysis
- The breakdown of red blood cells. Doctors check for excess hemolysis because it can also raise bilirubin.
- Glucuronidation
- The chemical step in which the liver attaches a sugar-derived molecule to bilirubin so it dissolves in water. It runs slower in Gilbert’s syndrome.
Symptoms of Gilbert’s syndrome
Many people with Gilbert’s syndrome have no symptoms at all; around 30 percent are only diagnosed because a blood test shows a raised bilirubin level. When symptoms do appear, they are usually mild and come and go.
Mild yellowing of the skin or eyes
Episodes of jaundice are the most common sign. On brown or black skin the change is often easier to see in the whites of the eyes.
Tiredness
Some people feel more fatigued during an episode, although this is not experienced by everyone.
Brain fog
Some people report difficulty concentrating, feeling mentally slowed down or having trouble finding the right words. Brain fog is not specific to Gilbert’s syndrome, so persistent or severe changes in thinking should be discussed with a clinician.
Mild abdominal discomfort
A vague ache or unsettled feeling in the upper abdomen can accompany higher bilirubin levels.
Symptoms that follow triggers
Episodes tend to appear after fasting or skipped meals, dehydration, illness, poor sleep, heavy exercise, alcohol or menstruation.
How it is diagnosed
Gilbert’s syndrome is diagnosed with blood tests. The typical pattern is a mildly raised level of unconjugated bilirubin with normal results on the other liver tests and a normal blood count. A genetic test for UGT1A1 is sometimes used to confirm the diagnosis.
Treatment and management of Gilbert’s syndrome
There is no cure for Gilbert’s syndrome, and medical treatment is not usually needed because it does not cause serious health problems. Management focuses on avoiding the things that trigger episodes.
Track episodes and triggers
Note when yellowing, tiredness or discomfort appears and what was happening: a missed meal, a short night of sleep, an illness. Patterns help you avoid triggers and give your doctor useful information.
Eat regularly and stay hydrated
Long gaps between meals and low fluid intake are among the most common triggers. Regular meals and plenty of water help keep bilirubin steadier.
Prioritize sleep and manage stress
Poor sleep and physical or emotional stress can raise bilirubin. Consistent sleep and rest during illness can reduce episodes.
Exercise sensibly
Regular moderate activity is fine. Very strenuous exertion, especially while under-fueled or dehydrated, can trigger an episode.
Check before starting new medicines
Speak to a doctor or pharmacist before taking a new medicine. Some, such as statins, may call for closer monitoring, and a few drugs (including certain cancer and HIV medicines) are processed by the same enzyme.
Keep up routine check-ups
Repeat blood tests at the intervals your doctor recommends, particularly if your jaundice changes or new symptoms appear.
Who does Gilbert’s syndrome commonly affect?
Typical age of recognition
Adolescence and young adulthood
It is present from birth, but is usually noticed in the teens or twenties when bilirubin first rises.
Sex
More common in men
Men are diagnosed more often than women, partly because they tend to have higher baseline bilirubin levels.
How common
3 to 7 percent
Estimated share of people in the United States who have it. It occurs worldwide.
Family history
Inherited
It is passed down in families, so relatives may also have raised bilirubin without knowing why.
Associated conditions
Type 1 diabetes
It is seen more often in people with type 1 diabetes, and may be linked with a slightly higher chance of gallstones.
Things to avoid
Prolonged fasting and crash diets
Going many hours without food, or severely cutting calories, is one of the most reliable ways to push bilirubin up.
Dehydration
Not drinking enough, or losing fluids through illness, heat or heavy sweating, can trigger an episode.
Heavy alcohol use
Alcohol can raise bilirubin in people with Gilbert’s syndrome and adds strain to the liver generally.
Sleep deprivation and extreme exertion
Long stretches of poor sleep or exhausting workouts without adequate fuel and fluids are common triggers.
Starting medicines or supplements without checking
Always mention Gilbert’s syndrome to prescribers and pharmacists, and check before taking new medicines or supplements.
“Liver cleanses” and detox products
Gilbert’s syndrome does not need cleansing, and there is no good evidence these products help. Some can harm the liver.
Assuming every episode of jaundice is Gilbert’s
New, worsening or persistent jaundice should be checked, even if you already have a diagnosis, because it can have other causes.
Questions to ask your doctor
Bring these to your next appointment, and write down the answers so you can refer back to them.
- Do my results confirm Gilbert’s syndrome, or do I need more tests to rule out other causes?
- Would a genetic test for UGT1A1 be useful in my case?
- What bilirubin level is normal for me, and at what level should I contact you?
- How often should my bilirubin and liver function tests be repeated?
- Are any of my current medicines or supplements affected by Gilbert’s syndrome?
- What should I tell other doctors, dentists or surgeons before a procedure or a new prescription?
- Which triggers should I look out for, and what should I do during an episode?
- Should my family members be told or tested?
- Which symptoms mean I should seek urgent care?
Common questions about Gilbert’s syndrome
What is Gilbert’s disease?
Gilbert’s disease, more commonly called Gilbert’s syndrome, is a common inherited condition in which the liver is slower than usual at processing bilirubin, a yellow pigment made when red blood cells break down.
The result is a mildly raised level of bilirubin in the blood that rises and falls over time. Most people have no symptoms, and some notice mild, temporary yellowing of the skin or eyes. It is harmless, usually needs no treatment, and does not damage the liver.
Is Gilbert’s syndrome an autoimmune disease?
No. Gilbert’s syndrome is not an autoimmune disease. It is a genetic condition caused by a change in the UGT1A1 gene, which reduces the activity of a liver enzyme that processes bilirubin.
In an autoimmune disease the immune system attacks the body’s own tissue. In Gilbert’s syndrome the immune system is not involved. Autoimmune liver conditions such as autoimmune hepatitis can also raise bilirubin, but they are separate conditions and usually cause other abnormal liver test results. If your bilirubin is raised along with other liver results, your doctor can work out which is responsible.
What is jaundice?
Jaundice is a yellow tint to the skin, the whites of the eyes and the inside of the mouth. It happens when there is more bilirubin in the blood than the liver can clear.
Jaundice is a sign rather than a disease in itself, and it has many possible causes. It usually becomes visible once bilirubin rises above roughly 2 to 3 mg/dL (34 to 51 µmol/L). On brown or black skin it is often easiest to spot in the whites of the eyes. Jaundice that is new, or that has not been explained, should always be checked by a doctor.
What causes jaundice?
Jaundice is caused by a build-up of bilirubin in the blood. The causes fall into three groups:
- Before the liver: too many red blood cells breaking down at once (hemolysis), as in hemolytic anemia.
- In the liver: hepatitis (viral, alcohol-related or autoimmune), cirrhosis, some medicines, and inherited conditions such as Gilbert’s syndrome.
- After the liver: a blocked bile duct, for example from gallstones or a growth in the pancreas.
Newborn jaundice is also common in the first days of life because a baby’s liver is still maturing. It is usually mild and is monitored by the baby’s care team.
What is bilirubin?
Bilirubin is an orange-yellow pigment made when old red blood cells are broken down. The liver converts it into a water-soluble form, it leaves the body in bile and stool, and it is what gives stool its brown color.
Blood tests report two types. Unconjugated (indirect) bilirubin has not yet been processed by the liver. Conjugated (direct) bilirubin has been processed and dissolves in water. In Gilbert’s syndrome it is the unconjugated type that is raised.
What are normal bilirubin levels?
In healthy adults, total bilirubin is usually about 0.1 to 1.2 mg/dL (roughly 2 to 21 µmol/L). Reference ranges differ slightly between labs, so compare your result with the range printed on your report.
In Gilbert’s syndrome, total bilirubin is usually mildly raised, typically under 3 mg/dL (51 µmol/L), and most of it is the unconjugated type. Levels move up and down and are often highest after fasting, illness or dehydration. Newborns have different, age-specific ranges.
| Measurement | mg/dL | µmol/L |
|---|---|---|
| Total bilirubin (typical adult range) | 0.1 to 1.2 | 2 to 21 |
| Direct (conjugated) bilirubin | Up to 0.3 | Up to 5 |
| Total bilirubin often seen in Gilbert’s syndrome | About 1.2 to 3 | About 20 to 51 |
Values are typical adult ranges and vary by lab, age and sex.
Can high bilirubin cause death in adults or children?
In Gilbert’s syndrome, no. The raised bilirubin is mild, does not damage the liver or brain, and does not shorten life expectancy.
Very high bilirubin from another cause can be serious because it points to an underlying problem such as severe liver disease or a blocked bile duct. In newborns, extremely high unconjugated bilirubin that goes untreated can enter the brain and cause a type of brain damage called kernicterus, which is why jaundice in babies is monitored closely and treated, usually with light therapy (phototherapy). In adults, the danger comes from the underlying condition rather than from bilirubin itself.
Get urgent medical help for jaundice with abdominal pain, fever, confusion or drowsiness, vomiting blood, or black or pale stools. For babies, seek care right away if jaundice appears in the first 24 hours, spreads, or comes with poor feeding or unusual sleepiness.
What does bilirubin in urine mean?
Bilirubin in urine (bilirubinuria) usually means there is a problem with the liver or bile ducts. Healthy urine contains no detectable bilirubin.
Only conjugated bilirubin dissolves in water, so only that type can pass into urine. Gilbert’s syndrome raises unconjugated bilirubin, so it does not normally cause bilirubin in the urine or dark urine. If it shows up on a urine test, or your urine looks dark brown or tea-colored, ask your doctor to check for causes such as hepatitis, gallstones or a blocked bile duct, especially if you also have pale stools, itching or jaundice.
Living with Gilbert’s syndrome? Track it with Loops
Log your symptoms and blood results, spot your triggers, and walk into every appointment prepared.
Sources
- Gilbert’s syndromeNHS
- Gilbert syndromeMedlinePlus Genetics, U.S. National Library of Medicine
- The genetic basis of the reduced expression of bilirubin UDP-glucuronosyltransferase 1 in Gilbert’s syndromeBosma PJ et al., New England Journal of Medicine, 1995
- Gilbert syndromeFretzayas A et al., European Journal of Pediatrics, 2012