Bilirubin is a bile pigment. The substance is one of the main components of bile in the body. Bilirubin is released as a result of the breakdown of proteins containing complex compounds. An increase in pigment in the blood is associated with a violation of its breakdown.

Mechanism of pigment formation

Proteins that contain heme, a complex compound, participate in cleavage reactions.

Heme contains substances:

• Hemoglobin– iron-containing protein;
• Myoglobin– oxygen-binding protein;
• Cytochromes- membrane proteins.

Hemoglobin is broken down in cells:

• Bone marrow;
• Spleen;
• Lymph nodes;
• Liver.

Bilirubin is a product of red blood cell metabolism and the result of the transformation of complex compounds. This pigment is called non-cohesive (indirect). After breakdown, the substance enters the liver. There it reacts with glucuronic acid.

As a result, the pigment turns into a bound (straight) form. Processed substances enter the bile. After this, they leave the body with feces, turning it brown.

How is bilirubin formed?

Approximately 96% of bilirubin in the blood is in its indirect form. The rest, as a result of the reaction, can dissolve in water. This is direct bilirubin. It is filtered by the kidneys and excreted in the urine.

Norm

To check the level of bilirubin in the blood, donate biochemical analysis. Material for research is taken from a vein. The test is taken on an empty stomach. General norm pigment is reflected in the table. The data is relevant for people under 60 years of age.

Reasons for the increase

Liver healthy person regularly removes the substance with bile. Failures in metabolic reactions impede the natural release of bilirubin. The substance accumulates in the body. In this case, the pigment penetrates into the tissues, coloring them in yellow. A high level of bilirubin that has managed to bind in the liver is dangerous for the body. The pigment is toxic.

Total bilirubin increases for several reasons:

• Impaired flow of bile into the intestines from biliary tract , which occurs with cholelithiasis, inflammatory processes in the gastrointestinal tract;
• Liver diseases caused by disruptions in metabolic reactions - cirrhosis, hepatitis, hepatosis;
• Hemoglobin release with rapid destruction of red blood cells - hemolytic anemia;
• Intense tissue breakdown caused by injury or cancer;
• The sequence of reactions of transformation of pigment into bile is disrupted;
• Taking certain medications.

Indirect bilirubin is higher than normal when liver failure, Gilbert's syndrome - a disorder of liver synthesis at the cellular level. Gilbert's syndrome occurs when there is a deficiency of a liver enzyme.

Direct bilirubin is elevated in the blood due to pathologies of the biliary tract or is associated with a violation of the outflow of bile.

Symptoms

There are signs that indicate an excess of the level of yellow pigment:

1. Lack of appetite.
2. Unpleasant sensations and pain under the right rib.
3. Abdominal enlargement.
4. Urine becomes dark in color.
5. Fast fatiguability.
6. Strong headache.
7. Cardiopalmus.

Treatment

The goal of therapy is to reduce the level of bilirubin in the blood and eliminate associated symptoms. For this you need A complex approach. First of all, the doctor finds out the cause of the increased pigment. If the deviation from the norm is insignificant and is associated with congenital pathologies liver, drugs that lower bilirubin are used. During treatment, a special diet is followed.

Drugs that lower bilirubin

If the outflow of bile is impaired, it is prescribed choleretic drugs. They eliminate pain and fight bile stagnation.

There are several groups of such drugs that can normalize the condition:

1. Choleretics. They increase bile production. The drugs are prepared from herbal infusions or obtained synthetically. TO natural medicines with increased bilirubin include: sandy immortelle, pine, St. John's wort, etc. Popular medications: Allohol, Liobil, Cholenzym.
2. Cholekenetics. To eliminate congestion, Mannitol, Flamin, Holosas are prescribed.

Medicine to reduce bilirubin is prescribed taking into account chronic diseases And possible contraindications. Self-medication is unacceptable.

If the disease is hereditary, treatment is aimed at eliminating the symptoms.

Reduce pigment with medications:

• Choleretic agents;
• Sorbents – Activated carbon, Smecta, Polysorb;
• Herbal infusions.

Sometimes elevated bilirubin is associated with immune disorders, inflammatory processes in the liver.

In these cases, treatment is carried out with drugs:

1. Hepatoprotectors- these are means that provide positive influence on liver function, protect organ cells from damage;
2. Antibacterial drugs.
3. Antiviral drugs.
4. Enzymes– complexes that accelerate chemical reactions in organism. These include: Pancreatin, Mezim, Festal.

To reduce bilirubin levels after intoxication, it is necessary to improve metabolism and remove harmful substances from the body. To do this, take antioxidants and sorbents. IN severe cases appoint intravenous injections detoxification drugs and glucose. As a result, there is a decrease in the dangerous pigment in the blood.

If the increase in bilirubin is caused by Gilbert's syndrome, treatment with Zikrorin and Phenobarbital is prescribed. Enzymes will help relieve the symptoms of the disease.

At home

Bilirubin is reduced with decoctions medicinal plants. For example, milk thistle infusion.

Plant-based products are considered effective:

• Karsil;
• Essentiale forte;
• Rezalut Pro.

How to quickly normalize bilirubin levels?

There is no clear answer. The doctor prescribes treatment depending on the cause of the increase in pigment. Each case is individual. Treatment is complex and requires compliance strict diet. If you follow all the doctor’s instructions and exclude prohibited foods from your diet, your bilirubin level will return to normal faster.

Diet

During treatment, avoid foods that burden the liver.

These include:

• Coffee;
• Alcohol;
• Mushrooms;
• Radish;
• Fast food;
• Fried foods;
• Smoked meats;
• Spicy seasonings;
• Pickles;
• Preservatives;
• Sour fruits, berries.

Video - bilirubin test

What foods reduce bilirubin in the blood?

The basis of the diet high level pigment – natural food without dyes, preservatives and flavor enhancers.

• Egg white;
• Dairy products;
• Sweet fruits;
• Lean meat;
• Vegetables;
• Cereals;
• Fruit drinks;
• Mineral water;
• Herbal teas.

Consuming foods and drinks that reduce bilirubin will speed up your recovery.

Folk remedies

Before treatment with drugs alternative medicine consult a doctor, since the reason for the deviation is different for everyone. There is no single recipe that fits every case of violation. Treatment folk remedies practice along with drug therapy for a noticeable effect.

What lowers bilirubin levels:

1. A decoction of birch leaves. The leaves are dried and crushed. For the decoction, take 1 tbsp. funds for a glass of boiling water. Before use, the decoction is infused for 30 minutes, taken once a day before bedtime. Birch leaves remove toxins from the liver and improve its functioning.
2. Herb tea. To prepare the drink, take St. John's wort, motherwort and chamomile. Dry plants are crushed and poured with boiling water at the rate of 1 tbsp. per glass of water. The drink is left to brew for 30 minutes. Take 20-30 minutes before meals.
3. Beetroot juice. It is squeezed out before use. Beetroot components accelerate the flow of bile and help cope with problems of congestion. Drink juice before meals, 1/3 of a glass.
4. Decoction of corn silk. A pinch herbal remedy Brew with a glass of boiling water. After half an hour, the broth is ready for use. Drink the infusion 2 times a day, 1/2 cup.
5. Motherwort infusion. Brew 1 tbsp in a glass of boiling water. herbs. Leave for 30 minutes. Take 1 tbsp decoction. on an empty stomach.

Video: How not to turn yellow

Increased bilirubin during pregnancy

The concentration of yellow pigment increases during pregnancy. It's connected with rapid growth fetus Every week the pressure increases internal organs rises. Including the liver. As a result of compression, the outflow of bile is hampered. Stagnation occurs. This is why bilirubin accumulates.

During pregnancy, most medications are prohibited. To reduce bilirubin levels, you need to follow a diet and drink herbal teas. Infusions are also taken with caution, after consultation with a gynecologist.

Increased bilirubin levels in newborns

In infants, excess levels of the substance in the blood are common. The condition is called “newborn jaundice.” This condition is not life threatening and is considered physiological phenomenon. The reason is the reaction of destruction of hemoglobin during labor.

How can bilirubin be reduced in newborns?

When the deviation from the norm is insignificant, no measures are taken. Bilirubin quickly returns to normal without any help. If this does not happen, phototherapy is used - light treatment.

Phototherapy is a physiotherapeutic procedure that uses ultraviolet rays. The child lies under the lamps several times a day. In this case, bilirubin is converted into an isomer and removed from the body physiologically.

Plays an important role in reducing bilirubin breast-feeding. The more often the baby is put to the breast, the faster the yellow pigment returns to normal. The volume of fluid in newborns with jaundice is increased by 10-20%.

Consequences

The risk of complications increases if you ignore symptoms high bilirubin or refuse treatment.

Toxic substances released as a result of excess bilirubin negatively affect vital important organs, both in children and adults:

1. Brain. Under the influence of toxins, its functions are reduced.
2. Liver. The organ gradually deteriorates if left untreated.
3. Kidney activity decreases. As a result, the risk of infections and inflammatory processes increases.

Low bilirubin levels

The yellow pigment level rarely decreases. The deviation is associated with a decrease in the number of red blood cells in the blood.

Reasons for rejection:

• Blood cancer (leukemia);
• Kidney failure;
• High degree of intoxication;
• Tuberculosis.

Increased bilirubin in the blood is one of the signs of the underlying disease. The main thing is to establish the reason for the deviation. After that, go through complex treatment aimed at eliminating it.

Bilirubin is the most important bile pigment in humans, which has a red-yellow color. It is considered a product of the breakdown of hemoglobin and proteins in the blood such as cytochromes, catalase, peroxidase and myoglobin. About 85% of bilirubin comes from red blood cell hemoglobin. From 1 gram of hemoglobin approximately 35 mg of bilirubin is formed. From human body this pigment is excreted along with bile. It is this bile pigment that colors our bruises yellow. In this article, we will try to understand in more detail what direct and indirect bilirubin are, what are the differences between them and how bilirubin should be treated.

What is the difference between direct and indirect bilirubin?

Direct bilirubin can be excreted from the human body due to its excellent solubility. Its excretion occurs through the liver along with bile into the intestines and in small quantities through the kidneys with urine. Direct bilirubin is formed only in liver cells - hepatocytes.

Indirect bilirubin is much more toxic than direct bilirubin. Bilirubin is almost water-insoluble. It dissolves well in fats, for this reason, if excretion fails, it first accumulates in adipose tissue. Indirect bilirubin occurs in the Kupffer cells of the liver. Indirect bilirubin can be removed from the body only through transformation into direct bilirubin.

Comparing these two factions, it is clear that they are in no way similar to each other.

Factors that increase bilirubin in the blood.

The most basic reasons that can provoke an increase in bilirubin in the blood are:

Increased rate of destruction of red blood cells;

All kinds of disturbances in the process of bilirubin processing;

Impaired flow of bile;

Hemolytic anemia;

Hereditary deficiency of enzymes in the liver;

Cholelithiasis;

Jaundice and hepatic colic.

Symptoms of increased bilirubin.

An increase in bilirubin and factors that can cause this state. An increase in the level of bilirubin in the blood above 27 µmol/l leads to the formation of jaundice. There are several degrees of severity of jaundice: 1) light form- up to 85 µmol/l; 2) average - 86-169 µmol/l; 3) severe form of jaundice - more than 170 µmol/l). Increased bilirubin may manifest itself as the following:

Yellow skin color;

Increased body temperature;

Headache;

Great fatigue;

Darkening of urine to dark brown;

Unpleasant sensations in the area of ​​the left side chest.

Other signs of increased bilirubin: jaundice, hepatic colic, vomiting, bloating and diarrhea, decreased appetite, itching skin, discoloration of stool.

The above symptoms are the most common with increased bilirubin in the blood. Now we will consider with you how to treat such a disease.

How to lower bilirubin?

There are no universal remedies that reduce bilirubin by 100% today. It is possible to lower bilirubin levels only after identifying the main reason for its increase. For these purposes, it is necessary to carry out some analyzes.

To determine the degree of hyperbilirubinemia;

For the diagnosis of hemolytic anemia;

To diagnose urinary outflow disorders;

For the purpose of monitoring a patient who is taking medications with hepatotoxic properties.

Also, during treatment, the patient needs to completely change his diet. Spicy, salty, smoked foods and alcohol are excluded from it. It is forbidden to eat fried fatty foods, drink strong tea and sweet soda and eat all kinds of sweets. In order to “free” the liver, gallbladder and cleanse the intestines, you need to eat vegetables and fruits (fresh, boiled and baked), you should also include dairy products. During the treatment of increased bilirubin, the same drugs are used traditional medicine. For example, it is very useful to drink during treatment, tincture of motherwort, infusion of chamomile decoction and St. John's wort herb. These products will help cleanse and significantly improve the liver.

If you have elevated direct bilirubin, then in this case The reason is hidden in a violation of the outflow of bile. If indirect bilirubin is increased, then often this is just an indicator of a diseased liver or Gilbert's syndrome. After surgical treatment of the main disease, bilirubin levels will decrease significantly.

The materials are published for informational purposes only and are not a prescription for treatment! We recommend that you consult a hematologist at your medical institution!

A decrease in bilirubin in the blood plasma is a rather rare and dangerous phenomenon. What reasons low bilirubin in the blood, and what treatment will help eliminate the problem?

Bilirubin is an important pigment of the liver, blood and bile ducts. Most often, the blood shows increased bilirubin, but there are still cases when total bilirubin is decreased. What does this mean and what dangers do such biochemical blood test indicators pose?

The indicator value is lower< 3,4 мкмоль/л можно считать пониженным. Напомним, что нормальные показатели общего и прямого следующие:

Important! Low bilirubin in the blood is not normal, since it also indicates the presence of quite serious diseases.

Low levels of yellow pigment in the blood can be determined using a biochemical blood test.

Causes of low bilirubin in the blood

There are several reasons that can provoke a decrease in bilirubin in the blood, including:

1. Chronic renal failure.
2. Acute leukemia.
3. Tuberculosis.
4. Cardiac ischemia.

With such diseases, bilirubin is always below normal, which is the reason for a more thorough examination.

Note: Bilirubin levels also vary by gender. In women the number of this substance less because their blood contains fewer red blood cells.

Can reduce the concentration of bilirubin in the blood long-term use some medicines: penicillin, barbiturates, prednisolone. People who overindulge in coffee or alcohol also have much less yellow pigment. Often, low bilirubin can be diagnosed due to improper preparation or blood tests.

Important! Despite the achievements in modern medicine, the exact reasons why low bilirubin is diagnosed are unknown.

What to do if there is low bilirubin in the blood

When a person is diagnosed with low direct or, it is very important to determine the cause and undergo a comprehensive study. As with an increased concentration of yellow pigment in the blood, important stage therapeutic therapy counts proper nutrition, compliance with the physical activity regime.

Patients diagnosed with low bilirubin should avoid alcoholic beverages, acute and fatty foods. Very often, with such disorders, a person requires consultation with several specialists, including a cardiologist. It is possible to increase or normalize the level of bilirubin in the blood only after determining the main cause that provoked this condition.

Many people treat with folk remedies to increase bilirubin, but these methods can only act as adjuvant therapy to the main treatment. In addition, treatment should only be done under the supervision of a doctor and only after the underlying cause has been determined.

Called bilirubin. At normal functioning In the body, this pigment is neutralized by the liver. Also, thanks to metabolism, bilirubin passes on its own from the direct type to the free type, and then in the form of liquid it easily exits through the intestines along with bile. However, if some kind of malfunction occurs inside a person, then the pigment can begin to accumulate in the blood, and since it is very toxic, serious problems can begin if intervention is not done in a timely manner.

Form and norm of bilirubin

There are two types of bilirubin in human blood: unbound and direct.

Direct type is a pigment or fraction general level bilirubin, which is easily soluble and low toxic. This component is synthesized in the liver and then, after it has acquired a liquid state, the pigment goes to the intestines, after which it enters the large intestine and freely leaves the body. It is because of bilirubin that human stools have a brown tint and this. However, the whole process does not end there. A small proportion of bilirubin is absorbed into blood vessels and returns to the liver through the portal vein.

The unbound or indirect type is produced not by the liver, but by bile. For such bilirubin, the body uses the already lost circulatory system red blood cells. Its main location is blood serum, which is excreted by the excretory system. If the red blood cell count has decreased or increased, it means that the functioning of the liver or gall bladder has been disrupted in the body, and there is a possibility of developing dangerous pathologies.

There are standards by which the doctor determines the enzyme level. The indicator directly depends on the form and type of bilirubin. In the direct form in an adult normal indicator– 5.1-17 µmol/l. The indirect type norm is 3.4-12 µmol/l.

Of course, small deviations do not immediately indicate serious problems, however, consult a doctor and undergo additional examination it would be reasonable.

What does a decrease in bilirubin levels mean?

More often, doctors find that bilirubin levels increase. However, in Lately There were patients in whom the enzyme decreased to a critical value. Although this is rare, experts have begun to study in detail the causes of this condition, since a decrease in pigment can also lead to dangerous abnormalities and diseases.

Read also:

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Most often, low bilirubin can be indicated by an incorrect blood test. For example, if the patient drank alcohol before the analysis or drank coffee in the morning, the indicator may indicate an incorrect result. Also, glucocorticoids, phenobarbital and ascorbic acid negatively affect the level of the enzyme. Therefore, if a person takes these drugs, he should tell his doctor about it so that he understands the reason for the incorrect analysis.

Doctors do not fully understand what exactly causes a decrease in bilirubin, but this definitely indicates the sensitivity of the human body to some changes, factors and various features.

Causes of pathology

If a repeated biochemical blood test was performed correctly, and the indicator has not changed, then this decrease may indicate the following diseases:

If the patient is at least sixty years old, then a decrease in bilirubin may indicate the development of coronary heart disease, regardless of the degree of its development. In addition, at this age, bile pigment often decreases, which can also lead to this problem.

A decrease in pigment is only a consequence of some problem; only a doctor can accurately determine the cause.

Symptoms and causes of low bilirubin in pregnant women

Not so long ago, doctors claimed that a reduced level of bilirubin in the blood at the time of pregnancy is normal condition, and today this indicator signals pathological changes. A pregnant woman is given a full diagnosis and urgent medical intervention.

Read also:

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A well-known pathology at the time of a decrease in liver enzyme is ischemia of the heart and blood vessels. When carrying a fetus, such a diagnosis requires constant monitoring, so the woman may be admitted to a hospital.

During pregnancy, many diseases become more pronounced, as organs begin to work with double force and the load on the heart increases. The heart of the expectant mother pumps several times more blood, thanks to this everything comes useful material, both to the mother’s organs and to the baby himself. Therefore, if before pregnancy a woman had no complaints about cardiovascular system, this does not mean that now her heart will function as before. The disease may be affected by constitutional disposition.

The next factor indicating a decrease in bilirubin is kidney disease or pathological disorder. Excessive load on the excretory system can provoke dysfunction and disruption of the functionality of any organ, but first of all the impact is on the kidneys.

A low rate may also be due to the following reasons: violation blood pressure. If the pressure is unstable and constantly rises in the evening, this indicates problems with the renal system. It is necessary to additionally conduct a biochemical analysis that will confirm this assumption.

A pregnant woman should be very careful about her health, because now she is responsible not only for her life, but also for the full development of her unborn child. The slightest changes in the body should alert you expectant mother and encourage her to immediately conduct a comprehensive examination.

Since the main reason for low bilirubin is incorrect analysis, you need to know the basics and rules to obtain the correct result.

In order to exclude possible mistakes, the doctor prescribes additional analysis. That's why you need to carefully prepare for it. The following actions will be required:

1. First of all, you need to monitor the consumption of drinks and liquids. The day before the test, it is not recommended to consume nicotine, caffeine and completely abstain from alcoholic beverages. Here's the reception clean water, on the contrary, is useful: the more water, the better.
2. You should not take any medications the day before the examination, especially antibiotics and drugs that were not prescribed by the doctor himself. Before taking the test, you need to tell your doctor about your treatment and what medications you are taking. The cause may develop due to the accumulation of drugs in the patient’s blood. An incorrect test result can sometimes cost the patient’s life, so you need to take this seriously.

Important! If a repeated biochemical analysis showed low bilirubin, then there is no need to panic too much and go to extremes; nervous shock will only worsen the situation. It is necessary to carry out further diagnosis and determine the nature and cause of this condition.

Treatment and methods of normalization

Although the nature of low bilirubin has not been fully studied, experts have identified some factors that help normalize the level of the enzyme in the blood. Treatment includes the following procedures:

• you need to keep track of what exactly is in your daily diet; eating fatty, spicy, smoked and fried foods is completely contraindicated
• an active lifestyle can also harm the body, sports exercises are very useful, but only when everything is done normally and not excessively
• completely exclude strong ones from the list alcoholic drinks and coffee

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Indirect and direct bilirubin: features of exchange

What is bilirubin?

Bilirubin(lat. bilis bile + ruber red) is one of the yellow-red bile pigments.

Chemical composition bilirubin molecules - C 33 H 36 O 6 N 4. Molecular mass- 584.68. IN pure form bilirubin is crystalline substance, consisting of rhomboidal-prismatic crystals of yellow-orange or red-brown color, difficult to dissolve in water.

The bilirubin molecule is based on four pyrrole rings inherited from hemoglobin. Two hydroxyl groups cause acidic Chemical properties bilirubin and its ability to form salts.

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Bilirubin: modern theoretical concepts

Modern representations about bilirubin differ significantly from those that existed 15-20 years ago. In particular, the view of bilirubin as clearly a waste substance has been revised. About antioxidant properties bilirubin, about delta-bilirubin, etc...

How is bilirubin formed in the body?

The formation of bilirubin occurs mainly from hemoglobin in the blood. Hemoglobin is found inside erythrocytes (red blood cells).

The destruction of eryth-ro-cy-ts leads to the liberation of the he-mo-glo-bi-na within them

The lifespan of an erythrocyte is 110-120 days. Red blood cells that have served their time are destroyed and replaced with new ones, and the released hemoglobin is utilized. Bilirubin is one of the products of hemoglobin processing. During the day, a healthy person replaces about 2 * 10 8 red blood cells and releases up to 6 g of hemoglobin.

The conversion of hemoglobin to bilirubin is a complex and multi-stage biochemical process and occurs with the formation of a large number of intermediate substances.

Bilirubin exists in the body in two main forms:

• indirect bilirubin, also known as free bilirubin, also known as unconjugated bilirubin (the names “unconjugated” and “conjugated” are used in the West)
• direct bilirubin, aka bound, aka conjugated

Total bilirubin as an independent chemical compound does not exist. Direct and indirect bilirubin together make up total bilirubin:

total bilirubin= direct bilirubin + indirect bilirubin

Pathways for the conversion and excretion of bilirubin.

Scheme 1. Indirect and direct bilirubin - ways of transformation and excretion from the body.

In the chain of biochemical reactions, the first to be formed is indirect or free bilirubin.

The breakdown of hemoglobin and its conversion into indirect bilirubin occurs mainly in the reticuloendothelial system:

• 80% of the total amount is in the Kupffer cells of the liver
• in cells bone marrow
• in spleen cells
• in histiocytes connective tissue all organs (in small quantities)

From tissues, almost insoluble indirect bilirubin is transported to the liver by blood albumin proteins.

An adult produces 300 micrograms of bilirulin per day. All bilirubin must be eliminated from the body, since it is a tissue poison. However, the poor solubility of indirect bilirubin does not allow it to be removed in the biochemical structure in which it exists. To do this, bilirubin must be converted into a soluble form. Delivered by albumin to the liver blood capillaries, so-called sinusoids, indirect bilirubin passes into the liver cells, freeing itself from its temporary connection with the protein molecule. Inside the liver cells-hepatocytes, on the surface of special intracellular formations - microsomes, indirect bilirubin, with the participation of the enzyme UDP-glucuronyltransferase, binds to glucuronic acid and is converted into direct or conjugated bilirubin.

indirect bilirubin + glucuronic acid = direct bilirubin

Direct bilirubin is excreted with bile into the intestines. In the large intestine, through the efforts of the microflora living in it, direct bilirubin undergoes further transformations. A small part of intermediate compounds (mesobilinogen, stercobilinogen, etc.) is absorbed back into the blood. Subsequently, these substances are caught by the liver and, after transformation into direct bilirubin, are again sent with bile to the intestines. Only a small part of them is excreted by the kidneys in the urine in the form.

Juxtra-tablet asks:

This means that free bilirubin is first formed, and after combining with glucuronic acid it turns into bound bilirubin. It's clear. But I don’t understand why it’s called “indirect” and “direct”. Indirect because it’s curved or what?

These names of the two types of bilirubin are due to the peculiarities of their laboratory diagnostics.

Since indirect or free bilirubin is adsorbed on albumin proteins, its detection in the test serum does not occur directly, but in two stages. First, ethanol or urea is added to the test tube to precipitate albumin, and only after that the reagent is added.

Direct bilirubin is immediately determined by adding a reagent.

How does direct bilirubin differ from indirect bilirubin?

• Indirect bilirubin is the precursor of direct bilirubin.
• Indirect bilirubin is much more toxic than direct bilirubin.
• Only direct bilirubin can be excreted from the body due to its good solubility. Its excretion occurs through the liver with bile into the intestines and in small quantities through the kidneys with urine.
• Indirect bilirubin is practically insoluble in water, but is highly soluble in fats, therefore, when excretion is impaired, it first accumulates in adipose tissue, as well as in lipid-rich brain tissue. Indirect bilirubin can be removed from the body only through transformation into direct bilirubin.
• The liver plays a leading role in the production of both forms of bilirubin, but this process occurs in its different structures: indirect bilirubin is formed in the Kupffer cells of the liver, and direct bilirubin is formed only in liver cells - hepatocytes.
  Although Kupffer cells are located in the liver, they perform their own task and functionally belong to the reticuloendothelial system. Its elements are located in many organs. 20% of indirect bilirubin is produced outside the liver.
  It should be said that indirect bilirubin produced in the liver has no priority over bilirubin produced outside of it. Just like bilirubin from other organs, it enters the bloodstream and becomes the general queue for processing by the liver into direct bilirubin.