The liver is your largest internal organ. About the size of a football, it's located mainly in the upper right portion of your abdomen — beneath the diaphragm and above your stomach. A small portion extends into the upper left quadrant.
Gilbert (zheel-BAYR) syndrome is a common, harmless liver condition in which the liver doesn't properly process bilirubin. Bilirubin is produced by the breakdown of red blood cells.
Gilbert syndrome is an inherited genetic condition. You might not know you have Gilbert syndrome until it's discovered by accident, such as when a blood test shows raised bilirubin levels.
Gilbert syndrome requires no treatment.
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The most frequent sign of Gilbert syndrome is an occasional yellowish tinge of the skin and the whites of the eyes as a result of slightly higher levels of bilirubin in the blood. In people with Gilbert syndrome, bilirubin levels may increase due to:
- Illness, such as a cold or the flu
- Fasting or eating a very low-calorie diet
- Strenuous exercise
When to see a doctor
Make an appointment with your health care provider if you have jaundice, which has many possible causes.
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Gilbert syndrome is caused by a modified gene you inherit from your parents. This gene usually controls an enzyme that helps break down bilirubin in your liver. When you have an ineffective gene, your blood contains excess amounts of bilirubin because your body doesn't produce enough of the enzyme.
How the body processes bilirubin
Bilirubin is a yellowish pigment made when your body breaks down old red blood cells. Bilirubin travels through your bloodstream to the liver, where the enzyme breaks down the pigment and removes it from the bloodstream.
The bilirubin passes from the liver into the intestines with bile. It's then excreted in stool. A small amount of bilirubin remains in the blood.
How the modified gene is passed through families
The modified gene that causes Gilbert syndrome is common. Many people carry one copy of this gene. In most cases, two modified copies are needed to cause Gilbert syndrome.
Although it's present from birth, Gilbert syndrome usually isn't noticed until puberty or later, since bilirubin production increases during puberty. You have an increased risk of Gilbert syndrome if:
- Both your parents carry the modified gene that causes the disorder
- You're male
The low level of the bilirubin-processing enzyme that causes Gilbert syndrome may also increase the side effects of certain medications, since this enzyme plays a role in helping clear these medications from your body.
These medications include:
- Irinotecan (Camptosar), a cancer chemotherapy drug
- Some protease inhibitors used to treat HIV
If you have Gilbert syndrome, talk to your health care provider before taking new medications. Also, having any other condition that impairs the destruction of red blood cells may increase your risk of developing gallstones.