Bilirubin explained

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This post explains what bilirubin is, why it’s relevant to Gilbert’s Syndrome, what can increase and what can decrease your bilirubin levels.

All about Bilirubin.

If you’ve been diagnosed with Gilbert’s Syndrome, then you’ve most probably been told that your bilirubin levels were high.  It’s one of the most common ways of determining that a patient has Gilbert’s Syndrome, and usually happens after general blood tests.

What is Bilirubin? 

Bilirubin comes from the blood when blood cells become old, and die.  Hemaglobin, the substance in blood that carries oxygen, is broken down to heme and globin and is passed onto the liver. Bilirubin is formed from the heme part of hemaglobin, and is a bright greenish yellow colour.

The bilirubin is not water soluble when it gets to the liver, and needs an enzyme to become so, then it can be easily passed out of the body.  The water soluble substance now passes through the gall bladder as bile and into the small intestine where it continues to be processed by bacteria in the intestines, and is passed out through the faeces and urination.

The enzyme that converts bilirubin

This enzyme that makes the bilirubin water soluble is called glucuronyl transferease, known as UGT for short, and is what people with Gilbert’s Syndrome are genetically lacking.  This means that the bilirubin is not ‘conjugated’ or converted so that it can easily leave the body.

The enzyme also uses blood sugar to help in processing bilirubin, which is one reason why missing meals can affect you.  It’s best to ensure you have regular small meals, and cut down on unrefined sugar and carbohydrates like white bread and pasta, so that the amount of enzyme you have can always have a stable supply of blood sugar to do its job.

There is always some bilirubin that is in the blood but this is chemically different from the ‘conjugated’ (also called ‘direct’) bilirubin.  GS sufferers however, have a lot more of this ‘unconjugated’ bilirubin because it hasn’t been disposed of as it should through the usual process. It’s the difference between the 2 types that tips off those conducting the lab tests on your blood that you have GS.

Note – recent feedback from people with Gilbert’s Syndrome indicates that when diagnosed, many  have both high conjugated AND unconjugated bilirubin. 

What’s too much bilirubin?

When bilirubin builds up in the blood at more than around around 2.0  to 2.5mg/dL total bilirubin, then the skin and eyes become discoloured with yellow, otherwise know as jaundice. Anything above 1.2 mg/dL is considered higher than normal.

Here’s an article from the Mayo clinic on the blood test and standard levels of bilirubin expected https://www.mayoclinic.org/tests-procedures/bilirubin/about/pac-20393041 

‘Typical results for a total bilirubin test are 1.2 milligrams per deciliter (mg/dL) for adults and usually 1 mg/dL for those under 18. Typical results for direct bilirubin are generally 0.3 mg/dL.’

Webmd has a page which also describes the test and the results, here: https://www.webmd.com/a-to-z-guides/bilirubin-test

What can cause a build up of bilirubin?

There are a number of reasons bilirubin builds up in the blood other than the lack of the enzyme, and it’s important to rule those out before diagnosing Gilbert’s Syndrome.  For example the patient’s bile duct could be blocked, or they could have a type of anaemia, or hepatitis.

Drugs can also affect the measurements of bilirubin, and many can increase it such as  steroids, some antibiotics, antimalarials, codeine, diuretics, MAO inhibitors, nicotinic acid, oral contraceptives, and others. 

We know that lack of sleep, stress, fasting and other burdens on your liver that preoccupy your Phase II pathways, where your deficient enzyme works, can also cause bilirubin levels to rise, in people with Gilbert’s Syndrome.

What can reduce bilirubin levels?

There are many lifestyle tips on this site that help to reduce bilirubin levels through managing factors that would cause it to rise. A healthy lifestyle is your best solution to living well with Gilbert’s Syndrome.

Drugs that clinical research studies show decrease bilirubin measurements include barbiturates, caffeine, penicillin and high dose salicylates.

Zinc sulphate reduced bilirubin levels in Gilbert’s Syndrome subjects in this study https://pubmed.ncbi.nlm.nih.gov/15114295/

Some studies show that in certain situations N-acetylcysteine (NAC), such as after a surgical bypass, can reduce bilirubin levels to some extent. https://www.sciencedirect.com/science/article/pii/S1015958419302428


There are differences in the UGT gene and the way it works in you, depending on your background and current lifestyle. You can find out more here https://gilbertssyndrome.org.uk/genes-gilberts-syndrome/

Symptoms from having raised levels of bilirubin include jaundice, and others, such as itching are addressed in other posts https://gilbertssyndrome.org.uk/posts-about-gilberts-syndrome/

Whilst the levels of bilirubin in Gilbert’s Syndrome will not cause permanent harm, they contribute to symptoms which cause feelings of being unwell, including jaundice, nausea, dizziness and itching. As you learn more about Gilbert’s Syndrome and managing your symptoms, you can feel healthier and happier with Gilbert’s Syndrome.

10 Replies to “Bilirubin explained”

  1. Hi
    I was diagnosed with GS a few years ago but never experienced any problems. I had my gallbladder removed and then contacted Covid and have had numerous problems since. I had my first episode of jaundice, have ongoing digestive issues, chronic pain but all tests are normal. Has anyone tried and had any success with acupuncture for GS?

    1. Hi Tricia, I’m sorry to hear you’ve had problems recently. Certainly as women age our hormonal status also impacts our Gilbert’s Syndrome too. You ask a great question, and I’d love to hear if acupuncture has helped anyone. I’m not sure how much impact it would have on the enzyme deficiency itself, but it might alleviate some of the symptoms such as anxiety and promote better sleep for example.

  2. I was diagnosed with this about 15 years ago. I have to say had the doctor not told me about it I would never have known I had it. However, in recent years, I’ve noticed I do get bouts of fatigue for no apparent reason and in the last two years, I’ve started getting anxious about relatively simple things. I didn’t know that anxiety was linked to Gilberts Syndrome. I’ve only just found that out.

  3. I am in my 30s and was diagnosed with gs last year…. I am Often having episodes of tiredness, ibs symptoms, nausea and fatigue….. I have never been a great sleeper so I don’t think it helps the gs

  4. Just been diagnosed with g’s. Thought they were pulling my leg as my surnames Gilbert. Maybe this is the reason I feel constantly drained sleepy and my mind surrounded by foggyness

    1. Wow, this site really helps me cope with the anxiety I have build becouae of the symptoms of GS…i lost weight and fell tired sometimes, and if you google these symptoms you get the worse dyagnoses ever…It has been a relief to see that I am not the only one who has a foggy mind, tired, lost weight and nauseea sometimes.

    2. Oh yes, that’s why.
      I’ve had GS for many, many, years and the fatigue, foggy brain and tiredness are debilitating. Watch out for any medication you are also taking, as there is some medications that can’t be taken by people who have GS.
      Thankyou for commenting, as you made my day with you comment. You would have thought the Doctor was pulling your leg. If only though, it is debilitating. You may also experience itching all over your skin from time to time.

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