Bile pigments in urine determine the type of bilirubin. Urobilinogen in urine: what does it mean, norm and deviations

Bile pigments in urine make it possible to assess the functional capacity of the gastrointestinal tract and identify initial signs of organ dysfunction. In a healthy person, the saturation of urine with urobilinogen does not exceed 17 mmol/l, and there is no bilirubin. Changes in the concentration of substances indicate disorders of various origins. By the nature of the increase and the ratio of substances, the doctor can tell at what level the failure occurred.

What do bile pigments in urine mean?

Bile pigments. Substances are capable of coloring the discharge in the appropriate color.

Normally, there is practically no bilirubin in the urine and is not detected by standard tests. The appearance of this fraction indicates bilirubinuria and the initial manifestations of hepatobiliary dysfunction: hepatitis, cirrhosis, liver tumor. In such cases, patients’ urine darkens and acquires the characteristic black-brown color of beer.

Urobilinogen - bilirubin transformed in the intestines, penetrates the kidneys and is excreted in the urine. The concentration of the substance is small, providing a straw-yellow color. The substance is constantly present in the bladder, indicating the normal functioning of the gastrointestinal tract and excretory system. After oxidation in air, it turns into urobilin and acquires a darker yellow color.

A significant increase in urobilin appears with an increase in blood bilirubin fractions, impaired reabsorption of breakdown products, and a block in the intestines. A negative urobilin test indicates a lack of bile outflow from the liver or severe damage to hepatocytes. An increase and decrease in bile pigment fractions are unfavorable signs of emerging disorders.

Kinds

The following urine pigments are known: bilirubin and urobilin. After heme is broken down, an unbound fraction of bilirubin circulates in the blood. This product is insoluble in liquid media and does not pass through the kidney filter into the urine. The substance is extremely toxic and needs to be neutralized. After entering the liver, the substrate is transformed: it combines with glucuronic acid, becomes hydrophilic, and low-hazard. The pigment then travels through the bile ducts into the small intestine. A small portion of bilirubin is reabsorbed by the portal vein system, and the remainder is excreted in the feces in the form of stercobilin. A portion of the conjugated substance enters the urine in the form of urobilinogen, where it is oxidized and becomes urobilin.

Reasons for appearance

In the normal state, bile in the urine is contained in minimal concentrations, which can fluctuate throughout the day, but do not exceed permissible limits. Normally, only urobilin is excreted in urine. The appearance of bound soluble bilirubin indicates pathology. At the same time, the substance itself is always elevated in the blood; the value of the indirect fraction may vary.

The absence of urobilin occurs with inflammation, tumor blockage of the bile ducts, impaired urination, and terminal liver lesions.

Video: All about bilirubin

In adults

In practice, doctors more often encounter disturbances in the excretion of heme breakdown products in the working population. Reasons that cause the appearance of bilirubin in urine:

• GSD, cholestasis;
• infections;
• intoxication, poisoning;
• hepatitis, Botkin's disease;
• cirrhosis;
• tumors of the hepatobiliary tract;
• removed gallbladder;
• intestinal obstruction;
• disorders of the heart and blood vessels leading to hypoxia of the parenchyma;
• hypothyroidism

Urobilin increases under the following conditions:

1. Diseases of the liver parenchyma, when reuptake of bilirubin does not occur and high concentrations of pigments remain in the blood, exceed the renal filter and are found in the urine.
2. Increased hemolysis of red blood cells. In addition to the physiological increase during menstruation and the neonatal period, it occurs with malaria, pneumonia, bleeding of various locations, disorders of the coagulation system, and sepsis.
3. Gastrointestinal pathologies with increased absorption of hemoglobin breakdown products: chronic constipation, intestinal obstruction.

In children

Often. The phenomenon is associated with physiological adaptation: the replacement of fetal hemoglobin is accompanied by an increase in the breakdown of red blood cells, and newborn jaundice occurs. It is important to monitor the dynamics of the condition: a rapid increase in the concentration and appearance of bilirubin in urine indicates a disruption of the natural process and the appearance of pathology.

At an early age, the cause of the appearance of pigments in urine is:

• genetic damage to the enzymatic transformation of bilirubin - Rotor, Crigler, Dubin-Johnson syndrome;
• disorders of the blood system (hemorrhagic diathesis, Werlhof's disease);
• hemolytic jaundice;
• intussusception followed by intestinal obstruction.

During pregnancy

At the time of gestation, the load on all organs and systems increases. Even in healthy women, an increase in urobilinogen can be detected in the urine. In this case, patients complain of darkening of the urine. In cases where there is pathology of the biliary system before pregnancy, the condition may worsen. Additionally, increased work of the heart and kidneys plays a role, contributing to an increase in the volume of blood volume and the concentration of absorbed substances.

Monitoring the level of bile pigments allows you to indicate the onset of an exacerbation. In a patient in an interesting position, it is necessary to exclude cholecystitis, viral hepatitis, pyelonephritis, and coagulation system disorders.

Diagnostics

Isolated slight darkening of urine is usually not a cause for concern. However, if you notice the following signs, you should consult a specialist:

• dark brown urine;
• discolored stool;
• fever, weakness;
• dyspeptic disorders (nausea, vomiting, stool disorders)
• skin itching;
• urinary disturbance;
• icterus of the skin, mucous membranes;
• pain in the right hypochondrium;
• the appearance of spontaneous hematomas.

First of all, you need to visit a therapist to prescribe standard urine tests to detect bile pigments. If violations are detected, the doctor determines the probable cause of the condition. With this in mind, it becomes clear which specialist to turn to for help. Blood diseases are corrected by a hematologist. Hepatitis is treated by an infectious disease specialist. Hepatobiliary tract disorders – gastroenterologist, surgeon if necessary.

For diagnosis the following is prescribed:

1. Complete blood count to determine anemia due to increased breakdown of red blood cells.
2. Blood biochemistry allows you to determine the concentration of fractions of bilirubin, alkaline phosphatase, protein, and get an idea of ​​​​the functioning of the liver.
3. Hemotest - analysis of stool for hidden blood if gastrointestinal bleeding is suspected.
4. Determination of markers of viral hepatitis during blood sampling.
5. Ultrasound of the abdominal organs.

The main way to identify pigments is a qualitative study of various environments of the body (urine, blood, feces). Special tests are carried out for the presence of urobilinogen: Florence, Gmelin, Rozin, Bogomolov. For reactions, iodine, nitric and hydrochloric acids are used, which combine with the components of bile to form a specific color. Depending on the intensity of the resulting shade, the laboratory technician in conclusion indicates the type of reaction: from weak (+) to strongly positive (++++).

Test systems with Ehrlich's reagent and the fluorescence method help to quantitatively establish bile pigments.

Treatment

Before starting therapy, it is necessary to reliably establish the cause of the appearance or increase of bile products in the blood. Collecting complaints, medical history, and diagnostic test results will help determine the type of disorder as accurately as possible.

Basically, correction of hepatobiliary tract disorders is carried out using traditional methods:

1. A therapeutic diet is mandatory; alcohol and smoking are contraindicated.
2. Viral hepatitis is treated using special algorithms.
3. Detoxification and plasma blood purification are carried out.
4. Hepatoprotectors and choleretic agents are prescribed.
5. Supportive (glucose, vitamins) and immunostimulating therapy is used.

Tumors, stones and other mechanical obstacles are subject to surgical removal. The optimal method is selected depending on the type of intervention and failure of conservative therapy.

Unconventional methods of treatment are acceptable in the presence of pathological bile pigments in urine. Usually special infusions of herbs with hepatoprotective properties or aimed at enhancing biliary function are used. Before starting to use traditional methods of therapy, it is necessary to consult with a specialist in order to avoid cross-effects of drug interactions.

Prognosis and prevention

With timely diagnosis and treatment of pathologies that lead to impaired excretion of bile pigments, the prognosis is favorable, leading to recovery and elimination of disorders.

To prevent the development of pathologies of the biliary tract it is necessary:

1. Observe personal hygiene rules.
2. Lead an active healthy lifestyle and eat right.
3. Treat gastrointestinal diseases in a timely manner.
4. Get vaccinated against hepatitis.

Video: How to lower bilirubin, thin bile.

Bile pigments (bilirubin, biliverdin, etc.) are formed during the breakdown of hemoglobin in erythrocytes and appear in the urine during jaundice. Urine containing bile pigments is yellowish-brown or green in color (a characteristic sign of jaundice).

Test for bilirubin with iodine solution (Rosin's test)

Carefully add a 1% alcohol solution of iodine or Lugol’s solution to 3 ml of urine. When bilirubin is present, a green ring forms at the boundary between both fluids. With normal urine the test is negative.

Gmelin's test for bile acids

Carefully add an equal volume of urine to 1 ml of concentrated nitric acid along the wall. In the presence of bile pigments, a green ring is formed at the border of the layering.

8. Petenkofer test for bile acids.

The reaction is based on the condensation of bile acids with hydroxymethylfurfural, formed under the influence of concentrated sulfuric acid from sucrose. The condensation product has a red-violet color.

Place 1 ml of urine in a test tube, add 5 drops of a 5% sucrose solution and carefully layer 1 ml of concentrated sulfuric acid along the wall of the test tube. In the presence of bile acids, a red-violet ring is formed at the layering boundary.

9. Jaffe test for urobilin.

Add a small portion of zinc chloride solution to 2 ml of urine. When shaken, a flaky precipitate appears, which must be dissolved in a concentrated ammonia solution (about 1 ml). Normally, a weak green fluorescence appears, which is pronounced in pathology.

10. Qualitative determination of indican in urine.

Indican, a potassium or sodium salt of indoxyl sulfuric acid, is found in trace amounts in normal urine. A lot of indican is found in the urine of herbivores, as well as in human urine with increased decay of proteins in the intestines, with constipation and intestinal obstruction.

Pour 4 ml of test urine into a test tube and add an equal volume of sulfuric acid while stirring. Then add about 1 ml of chloroform, 1 - 2 drops of potassium permanganate solution, close with a stopper and turn over several times without shaking. Place the test tube on a stand and observe the intensity of the chloroform layer turning blue. 13. Solve situational problems.

Be able to explain the principle of the determination method and the clinical and diagnostic significance of some biochemical parameters 1. Separation of blood serum proteins by paper electrophoresis and quantitative determination of protein fractions.

Separation and quantitation of proteins

blood serum fractions by electrophoresis on paper.

Principle of the method. Electrophoresis is the movement of charged particles in a field of direct electric current. The speed of movement of protein molecules in an electric field depends on the charge, molecular weight, pH, and ionic strength of the solution.

Serum proteins are placed on a strip of paper moistened with a buffer solution, through which a direct electric current is passed. At pH 8.6, serum proteins are negatively charged and, under the influence of an electric field, move to the anode.

Human blood serum contains various proteins. Using electrophoresis, 5 fractions are isolated on paper - albumin, α1-, α2-, β-, γ-globulins.

Clinical and diagnostic significance. Many pathological conditions are accompanied by quantitative changes in the ratio of protein fractions in the blood - dysproteinemia. A decrease in the content of the albumin fraction is characteristic of liver diseases due to a decrease in the protein-synthesizing function of hepatocytes. Hypoalbuminemia also accompanies kidney disease due to protein loss in the urine. An increase in the content of α1- and α2-globulin fractions is observed under stress, the presence of inflammatory processes due to “acute phase” proteins, collagenosis and metastasis of malignant neoplasms. The β-globulin fraction increases with hyperlipoproteinemia. The fraction of γ-globulins increases during immune reactions caused by viral and bacterial infections. A decrease in the γ-globulin fraction can occur in primary and secondary immunodeficiency.

Work order

1. Device design for electrophoresis. The device consists of a rectifier that supplies direct current at the required voltage, and a chamber for electrophoresis. The chamber itself consists of 2 baths; one of them has a fixed partition where a platinum electrode (+ anode) is placed, and the other contains a stainless steel electrode (- cathode). Between the baths filled with the appropriate buffer, there is a connecting bridge on which strips of special filter paper are placed.

2. Carrying out electrophoresis. Fill both chamber baths with a solution of veronal buffer with pH 8.6. There should be enough buffer solution in the baths so that it covers the fixed partition, but is below the movable partitions.

Insert electrodes into the baths. Cut strips of filter paper of the required size depending on the size of the chamber (usually 4-6 cm wide) and with a simple pencil mark the place where the serum will subsequently be applied (start). Soak these strips in Veronal buffer. Insert the connecting bridge into the bath chambers. Place strips of paper on dry plates with forceps, immersing the ends of the strips in baths with buffer, and apply 0.025-0.005 ml of serum to pre-marked areas of the paper at a distance of 5-6 cm from the edge of the bridge. Serum is applied from the cathode side.

Figure 1. Diagram of a chamber for electrophoresis of proteins on paper:

1-stabilizer; 2-chamber for electrophoresis; 3-buffer solution; 4-supporting connecting bridge-electrode; 5-filter paper for electrophoresis.

After applying the serum to the paper strips, the chamber is hermetically sealed with a lid. There is a locking clamp on the camera cover that is used to turn on the camera. The attached rectifier supplies the camera with a constant current of 2 to 4 mA at a constant voltage of 110-160V. Electrophoresis is carried out at a potential gradient of 3 to 8 V per 1 cm of strip at room temperature. Good separation occurs in 18-20 hours.

3. Turn off the device and identify protein fractions. Turn off the device. Remove the cameras and remove the paper strips from the device. Then each strip is placed in a drying cabinet for 20 minutes at a temperature of 1050C. In this case, the protein fractions are fixed on paper. Proteins are stained with a bromophenol blue solution for 30 minutes, then the electropherograms are washed with a 2% acetic acid solution. The resulting electropherograms are dried in air. Protein fractions turn blue-green.

4. Quantitative determination of protein fractions. The colored protein spots are cut out, the dye is eluted with a 0.01 N alkali solution. The color intensity of each fraction is determined colorimetrically using FEC.

Quantitative determination of protein fractions on an electropherogram can be determined in two ways: by elution of the dye and photocolorimetry and by the densitometric method.

albumins 55.4-65.9%

α1-globulins 3.4-4.7%

α2-globulins 5.5-9.5%

β-gdobulins 8.9-12.6%

γ-globulins 13-22.2%

Densitometric method. In a special apparatus (densitometer), a beam of light is passed through the electropherogram, the absorption of which depends on the optical density of the colored protein spots. The light passing through the electropherogram is captured by a photocell and converted into an electric current, the vibrations of which are recorded on a paper sheet in the form of a curve, each peak of the curve corresponds to a certain protein fraction.

Figure 2. Electropherogram of human serum.

Urobilin in urine is a chemical substance formed during the multi-level breakdown of hemoglobin molecules and gives urine a yellowish color.

An analysis of a patient’s urine for bile pigments takes into account the content of urobilin (urochrome), since its critically low or extremely high concentrations may indicate the presence of diseases in the human body.

Often the patient is told that he has urobilinoids in his urine. Below we will decipher and consider what their presence in a urine test means.

Urobilinoids literally means “urobilin-like”. The term “urobilinoids” is rarely used in the medical literature; they are more often called “urobilin bodies”. “Urobilin bodies” is the general name for a wide range of products of bilirubin metabolism - urobilin, mesobilinogen compounds (urobilinogen, stercobilinogen), stercobilin, and so on.

These chemicals are partially excreted in urine and partially in feces. Initially, bilirubin, which is a breakdown product of biliverdin (formed as a result of the breakdown of hemoglobin from red blood cells), is one of the main components of bile in humans and animals.

In this regard, when they talk about bile pigments in human urine, they mean the products of bilirubin metabolism. Bilirubin in urine in its pure form should not be present at all, like other proteins.

A urine test for urobilinogen allows you to identify bile pigments and promptly diagnose the presence of pathological processes in the liver, kidneys, gall bladder, and so on.

The color of urine containing bilirubin metabolic products becomes darker. This happens due to the natural coloring of urine with bile pigments, which are yellow and greenish in color.

The norm of urobilinoids in urine during general tests is rarely determined in numerical value, since their presence is negligible, and a positive reaction to a chemical substance is used to fully determine possible pathologies.

When numerically determined, the concentration of urobilinogen in urine analysis should normally not exceed 10 mg/l and should not be less than 5 mg/l. The normal level of urobilinogen in a child’s urine is 0-2 mg/l. In newborns, this level can be significantly exceeded, which is due to temporary physiological jaundice.

Etiology of increased urochrome levels

The content of urobilinogen in the urine of a child under three years of age should normally be the same as that of an adult, and varies from 5 to 10 mg/l.

The concentration of urobilinogen in urine may change with increased stress on the kidneys (use of diuretics, diarrhea, excessive fluid intake, etc.) or with chronic disease (failures in the liver or intestines).

The concentration of the substance in urine can vary either down or up, which, if there is a significant deviation from the norm indicated in the previous section, may indicate pathology (in particular, the liver).

The presence of bile pigments in urine can be caused by natural physiological or pathological processes in the human body.

High levels of urochrome: the most likely pathologies

If urobilinogen in the urine increases, the patient should be prescribed additional highly specialized diagnostics aimed at identifying one of the following diseases/pathological conditions:

• stagnation of bile. It is necessary to conduct an additional urine test for bile pigments and refer the patient for an ultrasound of the abdominal cavity;
• renal failure. Additionally, it is necessary to conduct tests for protein in the urine - with proteinuria, the level of urobilinogen is often increased;
• acute and chronic liver diseases: hepatitis, cirrhosis, benign or malignant tumors, and so on;
• a high level of urobilinogen (bile in the urine) indicates disturbances in the functioning of the stomach/intestines associated with dysbacteriosis.
• a high level of urobilinogen may indicate the development of a pathological condition of the circulatory system (anemia, etc.) associated with excessive destruction of red blood cells.

Low or absent urobilinogen levels

A general urine test allows you to accurately determine the presence or absence of urobilinogen in the urine. The absence of urobilinogen is a reason to refer the patient for highly specialized diagnostics in order to identify one of the following diseases/pathologies:

• cholestasis due to cholelithiasis, associated with blocking of the ducts with stones;
• kidney diseases leading to disruption of the filtration function of this organ of the urinary system. The most commonly diagnosed lesions are renal parenchyma.

Low levels or complete absence of urobilinogen in a child's urine is normal.

Urochrome in urine in a child

Urobilinoids in the child’s urine should be completely absent. If traces of urobilinogen are found in the child’s urine up to 2 mg/l, this is normal, but they may indicate the beginning of the development of physiological jaundice.

Children under 4 months of age are not likely to have urobilinoids in the urine if they are breastfed, since there are no prerequisites for the formation of the corresponding bacteria in the body. The concentration of urobilinoids in children over one year of age is identical to that of an adult.

Normal urobilinogen concentration during pregnancy

The urine of pregnant women contains more bile pigments. Changes during pregnancy are associated with increased load on the kidneys, which is manifested by increased urination due to increased fluid intake.

In this regard, the permissible norm for urochrome concentration during pregnancy is increased to 20 mg/l. Most women experience a more saturated color of urine during this period. Important! Acceptable rich dark yellow color.

But when a brown tint appears, we can talk about the admixture of blood and pus in the urine, which is not the norm, and you should immediately contact your doctor. In this case, the woman’s condition may remain normal.

Diagnosis and treatment of diseases

When a pathology is detected, the patient is first recommended to adjust the diet in order to reduce/increase bile production.

The main therapy should be aimed at eliminating or reducing the negative impact on the body of the disease, which causes a decrease/increase in the concentration of bile pigments. Self-medication is unacceptable. The use of traditional methods is allowed only after consultation with a doctor.

Testing urine for the presence of certain groups of organic substances in it makes it possible to become familiar with the functioning of the body. This kind of analysis is prescribed not only when the patient complains of certain changes, but also as a means of prevention after/during treatment. Timely identification of harmful substances will help get rid of errors in the functioning of the kidneys and other internal organs, and eliminate inflammatory processes.

Protein in a general urine test - characteristics and norms

The presence of protein in the urine is one of the symptoms that indicates a malfunction of the kidneys. In some cases, even in absolutely healthy people, under the influence of certain factors, urine testing can show the presence of protein.

What is the normal level of protein in urine for adults and children?

The level of this substance in urine at the time of morning collection should not exceed 0.033 g/l. However, this indicator may vary depending on lifestyle:

• For people who are engaged in heavy physical work, for athletes - 0.250 g/day.
• For people who do not lead an active lifestyle – no more than 0.080 g/day.

Causes of increased and decreased protein in urine in children and adults

There may be several factors that provoke the appearance of protein in the urine:

Bilirubin in a general urine test - characteristics and norms

During normal functioning of the body, the substance in question is excreted through the liver. When there is an excess of bilirubin in the blood, the function of its extraction is partially performed by the kidneys, which ensures the presence of this component in the urine.

Should there be bilirubin in the urine in children and adults?

In the absence of any pathologies in the functioning of the body, urine testing in children and adults should not show the presence of bilirubin in it.

Causes of bilirubin in urine in children and adults

The presence of the substance in question in the urine indicates a malfunction of the liver/kidneys.

The most common causes of bilirubin in urine are:

Glucose in a general urine test - characteristics and norms

Often, the increase (occurrence) of glucose in the urine occurs due to the inability of the kidneys to reabsorb glucose.

How much glucose should there be in the urine of children and adults according to the norms?

The substance in question may normally be present in urine, but its permissible concentration is limited: no more than 0.8 mmol/l. If, when testing urine, the glucose level exceeds the specified norm, a blood glucose test is prescribed at the same time.

Reasons for the increase (occurrence) of urine glucose in children and adults

The detection of this substance in the urine requires further, more thorough research, which will help establish the exact cause of this pathological phenomenon.

The most likely factors that cause the appearance of glucose in the urine in children and adults are the following:

Urobilinogen in general urine analysis - characteristics and norms

This substance is formed in the intestines from bilirubin. The main role in removing urobilinogen is assigned to the liver, but the kidneys also partially participate in this.

What should be the normal level of urobilinogen in urine in children and adults?

When testing morning urine, the substance in question is not detected in it. In general, no more than 6 mg may be present in the urine of adults and children throughout the day. urobilinogen. Some time after urine collection, urobilinogen is converted to urobilin.

Reasons for the presence (increase) of urobilinogen in urine in children and adults

The reasons that cause this pathological phenomenon when testing urine can be of a different nature:

Bile acids (pigments) in general urine analysis - characteristics and norms

The most common representatives of this group of substances are bilirubin and urobilinogen. Excretion of the components in question occurs through feces, less often through urine.

A distinctive feature of bile pigments when present in urine is its non-standard color: dark yellow, with a green tint.

What should be the normal level of bile pigment in urine in children and adults?

Bile pigments are regularly formed in the body under the influence of enzymes in the intestines. Often the main share of such substances (more than 97%) is excreted along with feces, in other cases through urine.

The permissible norm of the pigments in question in the urine of adults and children cannot exceed 17 µmol/l. An increase in this indicator is associated with serious diseases.

Causes of occurrence (increase) of bile pigment in urine in children and adults

The reasons causing an increase in the concentration of bile pigments when testing urine can be of a different nature:

Indican in general urine analysis - characteristics and norms

The substance in question is formed as a result of protein decay in the cavity of the small intestine. An increase in the level of indican concentration in the urine does not always indicate pathological conditions: this may be associated with poor nutrition (the predominance of meat foods in the diet).

What should be the normal content of indican in urine in children and adults?

This substance may be present in the urine of healthy people and children, but its amount is limited: 0.005-0.02 g/day. If there is an excess of indigan, the urine will have a blue tint, and the patient will complain of abdominal pain and diarrhea.

Reasons for increased urine indican levels in children and adults

Factors that provoke an increase in the level of indican concentration in the urine are often associated with errors in the functioning of the gastrointestinal tract:

• Inflammatory, purulent phenomena in the intestines: colitis, peritonitis, intestinal obstruction, chronic constipation, abscesses/abscesses in the intestines.
• Malignant formations in the stomach, intestines, liver.
• Diabetes.
• Gout.

Ketone bodies in general urine analysis - characteristics and norms

The formation of these substances occurs due to the decomposition of fatty acids. There are several types of ketone bodies: acetone, acetoacetic acid, hydroxybutyric acid.

Detection of the substances in question in urine is important for timely diagnosis and treatment of diabetes mellitus.

With inadequate drug treatment of diabetes mellitus, the level of ketone bodies in the urine will increase, which will indicate a deterioration in the functioning of the central nervous system.

How many ketone bodies should be in the urine of children and adults according to standards?

The presence of these substances in the urine of adults and children, even in small doses, is a sign of pathology.

Why do ketone bodies appear in urine in children and adults - reasons

The detection of these substances in urine may indicate the following pathologies:

Hemoglobin in a general urine test - characteristics and norms

This substance is formed during the destruction of the structure of red blood cells, after which the blood masses are replenished with a considerable amount of hemoglobin. The liver is responsible for removing the main part of hemoglobin; the kidneys take part in this process partially.

The question often arises: what are bile pigments in urine and what do they indicate. Urine contains many different substances. Some of them should be normal in it, others appear only in case of any malfunctions in the human body.

Moreover, the danger of a situation is always assessed by the number of such substances - the more there are, the worse the situation. The same applies to bile pigments.

What are bile pigments

Bile pigments are substances that make up bile. They can range in color from yellow and transparent to blue-green. They are formed against the background of various oxidation processes in the liver and other organs of the body, as well as due to the breakdown of hemoglobin.

Normally, pigments should be excreted in the feces in the form of reduced bilirubin. Their properties resemble acids, metals and salts, against which gallstones often form.

An important parameter to study is the presence or absence of these pigments in the urine. The kidneys are a filter organ. Accordingly, all metabolic products are excreted in the urine if their size is such that it passes through the organ’s filter. Bile pigments are always present in urine, but in small quantities. They are the ones who set the color of the biofluid. It is believed that it is impossible to calculate the minimum using conventional methods, and there is no particular need.

If the urine begins to darken, the doctor may suspect an increase in the concentration of these pigments. Moreover, a routine analysis carried out by professional laboratory technicians allows us to determine what pathology is developing. Studies prescribed for a particular disease help monitor the course of the pathology and the progress of treatment.

Performing an analysis for bile pigments allows you to determine which area is suffering and what should be given attention first.

Pigments and their role in the human body

The normal level of bile pigments is the key to ensuring that the body functions normally. The role of pigments in the human body is that they are products of metabolism and can indicate the onset of pathologies before they have yet produced clear symptoms. There are several main pigments.

Hemoglobin

Hemoglobin pigment is a respiratory blood pigment found in red blood cells. It is responsible for transporting oxygen from the lungs to the tissues.

In essence, it is not a bile pigment, but it is closely related to them, because they emerge from it. One of the main ones that manifests itself against the background of hemoglobin breakdown is bilirubin.

Bilirubin: features

In the urine of a healthy person, bilirubin is contained in small quantities, so it is not determined during the analysis. Therefore, it is believed that it is absent in urine. If its amount begins to increase, they say that the person develops bilirubinuria.

Bilirubin can change the color of the liquid - to the so-called beer shade. Bilirubin is formed during the breakdown of red blood cells. It cannot dissolve in water and is called free, which does not penetrate the kidney filter. Therefore, it does not appear in the urine, even if its amount is exceeded. But in the liver, such an element binds to glucuronic acid, resulting in the formation of conjugated bilirubin. But it can just be excreted in the urine. First, it passes through the ducts of the digestive organs, and then moves on.

If bound bilirubin begins to appear in the urine, the doctor may understand that some kind of pathology of the liver or biliary tract is occurring in the human body, for example:

• viral hepatitis;
• cirrhosis;
• metastases from cancer of the digestive system.

Urobilinogen

Urobilinogen can also be found in small amounts in the urine. When urine sits, it oxidizes and turns into urobilin, which is yellow. Therefore, during stagnation, the urine darkens due to accumulated urobilin. This also happens when dehydration is noted.

Normally, this substance should be contained in the analysis no more than 17 µmol per liter. If this amount increases, then a pathological condition such as urobilinogenuria develops.

Urobilinogen is the result of the interaction of bilirubin and bacterial enzymes, cells of the intestinal mucosa, which enter here with bile. With the development of certain pathologies, the formation of such a substance can increase and intensify. At the same time, there are situations when everything happens exactly the opposite, and the amount of pigment decreases.

An increase in urobilinogen in the urine indicates any diseases that occur against the background of destruction and breakdown of red blood cells. These include:

• malaria;
• hemolytic jaundice;
• bleeding of internal organs;
• lobar pneumonia, etc.

It is not so difficult to recognize the presence of urobilinogen in your tests - it is indicated by crosses on the analysis card. If the reaction is weakly positive, there will be one cross. If it is strongly positive, 4 crosses will be written on the form.

Urobilin

Another pigment that is formed during the breakdown of hemoglobin. This pigment is indirectly related to gallstones. At the same time, it indicates how the human urinary-excretory system works.

Biliverdin

Sometimes they can talk about the discovery of a pigment such as biliverdin. This is the green pigment of bile. It is essentially an intermediate product of the breakdown of hemoglobin. When it breaks down, globin and iron are released. When enzymes act on it, it is reduced back to bilirubin.

Urine analysis and pigments

Many may have a question: why is pigment analysis needed? A change in their concentration indicates pathology. And this is a fairly quick way to understand whether the body is functioning correctly. Plus, with the help of such a study, it is possible to determine developing complications that can develop against the background of a removed gallbladder, to see whether stones from the biliary system have been efficiently removed.

Urine color and pigments

You can recognize pigments in urine by its color. So, if they are not present or they are in extreme concentrations, it will be light. When urine darkens, they speak of problems in certain body systems.

Normal and pathological urine color

Normally, urine should be light yellow in color. It is also called straw. If it is too dark, closer to brown, doctors will prescribe additional research for diseases of the liver and digestive system as a whole. The urobilinogen level should vary between 5-10 units. If this level is higher, additional manipulations will also be prescribed to accurately determine any deviations.

But there are situations when the level of this pigment decreases. In this case, they speak of the presence of blockage of the bile ducts. They can be caused by:

• blockage in the form of a stone or tumor;
• suprahepatic jaundice;
• intoxication;
• cirrhosis;
• constipation

Rules for preparing for urine analysis

To get an accurate result, you need to approach the submission of material for research correctly. Immediately after collection, the urine can be placed in the refrigerator for 2 hours. But this is the case if it is not possible to immediately go to the laboratory.

You should take a portion of the material in the morning, ideally when nothing has been eaten or drunk yet. For a full study, 30-50 ml will be enough.

To prevent the result of a urine test for bile pigments from being distorted, you should wash yourself before collecting the material. Women are advised to cover their vagina with a tampon to prevent genital flora from getting into the urine.

Biochemical urine analysis as an additional diagnosis

If any excess levels of bile pigments appear, an additional biochemical urine test may be prescribed. It will be more detailed and will show more accurate parameters, as well as additional substances that may be released in certain pathologies. Here the indicators include creatinine, potassium, calcium, protein, etc.

What diseases do these pigments in urine indicate?

If malfunctions occur and pigments in the urine begin to appear or increase, doctors make a preliminary diagnosis. For example, in adults, the appearance of bilirubin in the urine indicates the development of:

• gallstones;
• various infections of the digestive system;
• poisoning;
• hepatitis;
• cirrhosis;
• tumors;
• complications due to the removed gallbladder;
• intestinal obstruction;
• disruptions in the functioning of the heart and vascular system;
• hypothyroidism. Against the background of physiological adaptation, a replacement of fetal hemoglobin is noted.

An increase in urobilin in adults appears when:

• certain liver pathologies;
• increased hemolysis of red blood cells;
• pathologies of the gastrointestinal tract that occur against the background of increased absorption of hemoglobin breakdown products, for example, constipation and obstruction.

Children may have their own reasons why urine test results change. In infants, bilirubin can be elevated even in normal conditions - the systems are still adapting, there is a replacement of fetal hemoglobin and is accompanied by the breakdown of red blood cells. Typically, children are diagnosed with neonatal jaundice at this point. Therefore, it is worth paying closer attention to how the situation develops. If a child’s increase in bilirubin production accelerates, it is clear to the doctor that some kind of pathology has begun, and measures should be taken urgently.