Physicochemical properties of urine. The process of urine formation: what is it and what does it consist of? What is urine called?

Thanks to modern laboratory research, such a complex substance can be thoroughly studied. This is necessary in order to assess the condition of the body, especially if there are complaints.

The urine of a healthy person can contain many different substances, but the main one is water. Nephrons are responsible for the formation of urine. To obtain primary urine, blood enters the glomeruli. It is filtered thanks to a special membrane of the nephrons.

All useful substances, as well as fluid and toxins, are removed from the blood. And all this rich composition ends up in the tubules and capsules of the kidneys. Then comes the reabsorption stage. Beneficial substances will be sent back into the blood through the vessels.

The urine of a healthy person may contain trace amounts of those elements that are necessary for the body to function properly. These substances should almost completely return to the bloodstream, and not exit with urine.

The last stage of urine formation includes the following “mix”: the secretion of the tubules is released into the primary urine, which includes hydrogen ions, potassium, ammonia and medications that a person takes. This mechanism is considered quite important, since it helps maintain the acid-base balance of our body.

The functioning of the kidneys depends on the proper functioning of the nervous and hormonal systems, as well as on the processes of breakdown of protein substances. When urine is ready to be released, it enters the ureter from the renal pelvis, then into the ureter. The last route will be through the urethra.

The urine of a healthy person can contain about 90% water, and the remaining 10% includes salts of sulfuric and phosphoric acid, potassium oxide, sodium chlorine. This also includes organic substances, represented by protein breakdown products - creatinine, urea, hippuric and uric acids.

The constant composition of the blood is ensured by the kidneys, removing excess salts from the body. The urine of a healthy person may contain desquamated epithelial cells lining the urinary tract, as well as gases, including carbon dioxide.

Lineup changes

The composition of excreted urine changes depending on the environmental conditions it is in, what the person ate the day before, how much water and other drinks he drank, as well as physical activity.

Less urine is produced if the body sweats a lot, and the person drinks little and eats dry food. It is logical to assume that cold and wet weather, coupled with a passion for soups and drinks, leads to the release of large amounts of urine.

At night, a healthy person urinates less often, or perhaps no urine is released at all. During the day everything is different. Going to the toilet is 5-6 times. Women tend to visit the restroom much more often.

Every patient has given urine more than once in his life, because at the slightest ailment, doctors prescribe a general blood and urine test.

Characteristics of urine

Specific gravity. This figure ranges from 1006 to 1028 g/l.

The normal color of urinary fluid is yellow. The less urine is produced, the darker it is. Some brightly colored foods also affect the color of medications.

A medium reaction between 4.5 and 6.5 is considered normal and is called slightly acidic. The more plant foods, the more alkaline the urine will be. Animal fats make urine “sour.”

Chemical indicators

The urine of a healthy person may contain small amounts of protein if the day before the patient:

• experienced stress;
• did physical labor;
• I overate foods that contain a lot of protein.

If glucose is found in the urine, they speak of glucosuria in a healthy patient if he:

• ate a lot of carbohydrates the day before;
• experienced severe psycho-emotional shocks;
• took any medications;
• poisoned by heavy metals.

Having removed all these reasons, urine returns to normal. The urine of a healthy person may also contain ketone bodies. They appear when there is an excess of fat and protein in the diet, along with a decrease in the amount of carbohydrates, as well as when there is a lack of fluid.

Sediment

There are no red blood cells in the urine of healthy people. Leukocytes, not exactly - there can be up to 8 of them. Epithelium is also allowed, but in small quantities.

The urine of a healthy person may contain salts, although this is already a sign of a metabolic disorder. You should change your diet so as not to lead to urolithiasis.

Finally, let's summarize. A person who does not have health problems urinates without any pain or difficulty. He goes to the restroom regularly and can endure it for a reasonable amount of time if necessary.

The secreted liquid looks normal and its amount does not change with the same drinking regime. As soon as you notice that your urine has changed, analyze the possible reasons. If you managed to eliminate them yourself and everything returned to normal, do not worry. Otherwise, you need to take a urine test first, and then seek help from a doctor.

During the day, about 60 g of substances are excreted from the body in urine: 35-45 g organic and 15-25 g mineral.

The chemical components of urine are represented by substances of both organic and mineral nature. The first include urea, creatinine, peptides, amino acids, uric acid, hippuric acid, and organic sulfates. The second ions include Na +, K +, Ca 2+, Mg 2+, NH 4 +, Cl -, HCO 3 -, H 2 PO 4 -, PO 4 3-, HPO 4 2-, inorganic sulfates.

Information on the excretion of these substances in the urine of a healthy adult is given in Table 3.

Table No. 3

Average composition of daily urine of a healthy person

Organic constituents of urine

1. Urea - the main organic nitrogen-containing component of urine. Urea accounts for 80-90% of the nitrogen-containing end products of metabolism excreted in the urine. On average, about 20-35 g of urea or 333-583 mmol/day are excreted from the body of an adult per day, which in terms of nitrogen is 6-18 g.

Urea excretion depends on the state of the gastrointestinal tract, liver and kidney functions, and metabolic rate.

Increased secretion of urea - hyperuriuria may be associated with a large intake of protein in food, is of a nutritional nature, in addition, hyperuriuria is observed in all diseases accompanied by increased breakdown of tissue proteins (febrile states, cachexia, hyperthyroidism, diabetes mellitus, etc.), as well as when taking certain medications (hormones).

Reducing the amount of urea excreted in the urine hypouriuria, is typical for diseases and toxic lesions of the liver, accompanied by liver failure, for kidney diseases with a violation of their filtration ability, as well as when using insulin and a number of other reasons.

2. Uric acid - the end product of the catabolism of purine nucleotides. During the day, a healthy person excretes about 0.3-0.6 g of uric acid or 1.6-3.54 mmol/day in urine. This value rarely falls below 0.5-0.6 g, even in the absence of purines in food, but can increase to 1 g or more when consuming foods high in nucleoproteins. The amount of uric acid excreted in the urine depends on its content in the blood and is determined by the ratio of the processes of glomerular filtration, reabsorption and secretion in the tubules, possibly with the participation of a specific carrier.

90-95% of the uric acid present in the ultrafiltrate is reabsorbed.

In newborn children, the excretion of uric acid is about 0.2 mmol/day, at the age of 1 month – 0.6 mmol/day, at 1 year – 1.2 mmol/day.

The first three months of a child's life are characterized by high excretion of uric acid. By 6 months, the proportion of urea increases, but the release of uric acid exceeds the corresponding values ​​in adults. These data indicate that at an early age in children, the main form of excretion of the final products of nitrogen metabolism is uric acid, which characterizes the uricotelic type of excretion of amine nitrogen.

Increased excretion of uric acid ( hyperuricuria), observed with leukemia, polycythemia, hepatitis, gout, as well as during treatment with aspirin and corticosteroids.

Hyperuricuria may be associated with overproduction of uric acid in the body due to increased breakdown of tissue structures or genetic disorders of individual enzymes - Lesch-Nyhan syndrome, etc.

Due to their low solubility in water, uric acid and its salts can precipitate and form stones in the lower urinary tract.

3. Creatinine - is also the end product of nitrogen metabolism. Formed in muscle tissue from creatine. Creatinine enters the urine mainly through glomerular filtration and in small quantities due to active tubular secretion. The daily excretion of creatinine is individual and constant for each person, reflecting mainly the volume of muscle mass of the body and averaging 4.4-17.7 mmol/day. (0.5-2g/day). The relationship between the amount of creatinine excreted in the urine and the amount of muscle tissue is expressed as the creatinine coefficient, i.e. the amount of creatinine excreted in 24 hours (in mg) per 1 kg of body weight. This coefficient ranges from 18 to 32 for men and from 10 to 25 for women; it is small in obese asthenic persons and high in persons of average height with developed muscles.

In newborns, creatinine excretion is 0.08 mmol/day; by 1 year of age this value is 0.7 mmol/day. Hypercreatininuria observed when eating a large amount of meat food, necrosis of soft tissues (muscles), prolonged crush syndrome, heavy muscular work, after removal of a hemostatic tourniquet, feverish conditions, pneumonia. Hypocreatininuria observed in chronic nephritis with uremia (renal failure), muscle atrophy, kidney degeneration, leukemia, and in old age.

In children, in addition to creatinine, creatine may appear in the urine - this is physiological creatinuria, which is due to the fact that the synthesis of creatine in a child is faster than the growth of muscle tissue. So, if only traces of creatine are detected in the urine of newborns, then by 1 month of life its amount increases to 0.07 mmol/day, and by 1 year – to 0.4 mmol/day.

Physiological creatinuria observed in old age and is associated with age-related degenerative changes in muscle tissue.

4. Total nitrogen - the sum of all nitrogen-containing components of urine is normally 10-16 g/day.

Hyperazoturia observed with increased breakdown of tissue proteins (diabetes mellitus, thyrotoxicosis, etc.), hypoazoturia- with a lack of protein in the diet, with impaired excretory function of the kidneys.

Urine is a product produced as a result of human activity. It is formed in the kidneys by tiny nephrons. The human filtering organ contains, as a rule, at least one million of these structural and functional units. Urine production is a natural physiological process that occurs from the time in the mother's womb until death. When it is violated, a person’s well-being significantly worsens, and the organs and systems of the body suffer.

Physiology

Normally, blood is filtered daily. In approximately 3 minutes, the entire volume of the vascular system passes through the paired organ. The main task of the kidneys is filtration. During blood purification, substances formed as a result of metabolic processes are removed from it. When processed by nephrons, they are converted into excrement - urine, which in healthy people leaves the body without problems. From the age of 3-5 years, a person can control the process of urination. If health indicators leave much to be desired, then not only the function of the paired organ is disrupted, but also the physicochemical properties of urine are distorted.

After cleansing the blood in the kidneys from metabolic products, biological fluid is formed. Next, it enters the pelvis, which delivers it to the ureters - hollow organs in the form of tubes that connect the filtering part with the storage bladder. Flowing through the channels, human urine is collected in a special bag - the bladder. Until it is full, a person does not have the urge to defecate. The sphincter reliably holds biological fluid, and its work is controlled by the spinal cord and brain.

When a person feels the urge to urinate, the smooth muscles of the bladder walls contract, and the sphincter, on the contrary, relaxes. As a result, the urethra opens, through which waste products flow out.

Urine indicators

Normally, the biological fluid formed by renal nephrons is yellowish in color. Depending on the type of diet and lifestyle, the shade may change. The chemical composition of urine differs from person to person. It can be used to determine the functioning of vital organs and identify some diseases. The composition of urine is an important indicator of the functioning of the body. It is difficult to find a person who has never taken a general or biochemical analysis. Determining physical and chemical parameters becomes a difficult task for laboratory technicians.

Urine volume

Together with urine, harmful substances that poison the body are eliminated from the human body. Therefore, it is important that daily diuresis is normal. It is influenced by the following factors:

• the amount of fluid consumed (this includes not only plain water, but also other drinks, including alcoholic);
• diet (number of meals, quality of food);
• temperature indicators of air and human body;
• arterial pressure;
• physical exercise;
• other indicators of the health status of organs and systems.

An adult who does not have any abnormalities produces urine in a volume of one and a half to two liters per day. The variability of indicators is noticeable when changing the diet, type of food, decreasing or increasing fluid intake during the day. Physical activity can affect the volume of urine. There are a number of pathological processes that are determined by the volume of fluid produced and the frequency of the urge to urinate. You can suspect a deviation from the norm on your own, but confirm it only with laboratory tests. Based on the patient’s complaints, the following diagnoses can be assumed:

1. polyuria – a condition in which daily diuresis exceeds 2 liters, subject to moderate drinking regimen;
2. anuria is a pathology in which a person produces no more than 50 ml of biological fluid;
3. oliguria – a moderate decrease in diuresis, in which the volume of urine is up to half a liter;
4. pollakiuria – frequent urge to empty the bladder;
5. olakisuria - rare urges that may be a variant of the physiological norm under certain conditions (for example, after childbirth or surgery);
6. nocturia is a condition in which a person has more urges at night than during the day;
7. dysuria – pain that occurs when urinating;
8. Enuresis is the uncontrolled release of urine during night sleep without first waking up.

Color

By definition, urine has a yellow tint. It may vary slightly depending on the amount of pigments contained in urine, called urochromes. The color is affected by the intake of brightly colored foods (beets, carrots) and the amount of liquid consumed. The use of certain medications can also cause discoloration. To clarify urine on your own, a person just needs to increase the volume of drinking water. If this technique does not help, then the color change may be associated with pathological processes occurring in the filtering organ and other body systems:

• deep red indicates the presence of blood particles;
• brown is an indicator of liver dysfunction;
• black becomes a sign of protein breakdown or a hereditary disorder of hormonal metabolic processes;
• white indicates the presence of fat emulsions or pus in urine;
• orange is a sign of dehydration and can appear as a result of the use of medications;
• green occurs with hypercalcemia or from the use of dyes;
• dark brown becomes the first symptom of infectious and inflammatory processes in the urinary system.

Smell

If a person does not have health problems, then the urine produced does not contain impurities, and there is no pungent odor. Urine smells specific, but not harsh. After prolonged contact with oxygen, the substances contained in the urine begin to produce ammonia. As a result, a characteristic unpleasant odor appears.

If urine smells unusual, this may also indicate various abnormalities and diseases. If the smell of acetone or fruit appears, diabetes mellitus is suspected. In this case, the chemical properties change, and ketone bodies are found in the urine. Infections of the urinary system are often accompanied by the appearance of a fetid and putrid odor. A person may associate this with smelly feet, feces, and rotten cabbage. If this condition is not a one-time occurrence and is observed regularly, then you should be concerned about your health.

Physical indicators

Equally important when studying urine is density and acidity. They cannot be identified visually, unlike color, transparency and smell. Normal urine acidity is in the range from 5 to 7 pH.

You should have an idea of ​​what these indicators mean. pH 1 is a caustic acid, and pH 14 is alkali. Pure water has an acidity index of 7.

The acidity of urine can be affected by food. When you eat too much protein, your urine becomes acidic. When a person eats citrus fruits in large quantities, the biological fluid takes on an alkaline environment.

The density of urine is determined from the ratio of its weight to volume. Urine tends to be mostly water. It also contains dissolved components and substances. Normal density varies in the range of 1005-1030 g/l. During general analysis, this indicator is calculated using the formula: weight divided by volume. If kidney function is impaired, these indicators may decrease.

Compound

Few people know what urine consists of. Most people assume that there is recycled water in the urine. However, there are also other chemical elements. The table clearly shows the normal content of components and the conditions under which these indicators change.

Urine use

Urine, acting as the final link in metabolic processes in the body, becomes an important element in the cycle of nitrogen and phosphorus. The components of urine, after entering the environment, are perfectly absorbed by plant rhizomes. It contains: ammonium, calcium, potassium, phosphorus, magnesium ions. For this reason, urine is recommended for use as fertilizer. It is important to know that such a substance is used only after fermentation.

Human and animal urine is used in pharmacology for the preparation of many medicinal and diagnostic substances. There are people who practice urine therapy. Doctors question the effectiveness of this treatment method, but do not speak out about its harm to the body. The urine of a healthy person is sterile and cannot cause harm even if consumed orally.

Fresh urine is used to make sympathetic writing devices. Once applied to the surface, it dries and leaves no trace. You can see the inscription after heating. In this case, the symbols will no longer be yellow, but dark brown.

To diagnose the functioning of the body, diagnostic manipulations with urine are performed. The most common and indicative is considered to be general analysis and biochemical analysis. If there is a deviation from the norm, the patient is prescribed a study according to Nechiporenko, Zimnitsky, Amburge.

A general urinalysis (UCA), also called a clinical urinalysis, is one of the most common laboratory tests performed for diagnostic purposes. It is prescribed for many diseases and includes the determination of up to 20 indicators, each of which helps in making the correct diagnosis. If you have been prescribed a general urine test, it will be useful to familiarize yourself with the rules for interpreting its results.

Why is a general urine test prescribed?

Urine (lat. urina), or urine, is a type of biological fluid secreted by the kidneys. Along with urine, many metabolic products are removed from the body, and therefore, by its characteristics, one can indirectly judge the composition of the blood and the condition of the urinary tract and kidneys.

Urine includes substances such as urea, uric acid, ketone bodies, amino acids, creatinine, glucose, protein, chlorides, sulfates and phosphates. Analysis of the chemical and microbiological composition of urine plays an important role in diagnosis: any deviations from the norm indicate abnormal metabolism in the patient’s body.

When is a general urine test prescribed? This study is necessary for any diseases of the genitourinary and endocrine systems, for abnormalities in the functioning of the cardiovascular and immune systems, as well as for suspected diabetes. Also, a general urine test is prescribed for patients who have had a streptococcal infection. In addition, it is carried out for preventive purposes and to monitor the dynamics of diseases.

How to take a general urine test?

To ensure that the analysis results reflect the true clinical picture, preparation for the procedure and urine collection are carried out in compliance with a number of rules.

Basic requirements when preparing for a general urine test:

• You must purchase a special sterile container for collecting fluid in advance from a pharmacy or from a doctor;
• collection should be carried out in the morning: for analysis it is recommended to use the morning liquid that has accumulated overnight, while the “average portion” of a stream of urine is important for collecting into a container;
• the night before, you should stop taking any medications that could affect the composition of your urine (it’s best to consult your doctor about this), as well as alcohol and coloring foods (beets, carrots, rhubarb, bay leaves, etc.);
• morning urine is collected on an empty stomach, you should not eat or drink anything before;
• Before collecting the analysis, you should not be too cold or overheated.

Collection rules:

• it is advisable to collect 100–150 ml (or 2/3 of a special container);
• before collection, you need to thoroughly clean the genitals: in some cases, women are recommended to use a tampon;
• the collected liquid should be delivered to the laboratory as soon as possible (with a delay of no more than 2 hours);
• if the liquid needs to be stored for some time, then the container can be placed in a dark and cool, but not too cold place;
• It is advisable to transport the container at positive temperatures in the range of 5-20 degrees.

What does a general urine test show: deciphering the results

Decoding the results of a general urine test will help you understand the results obtained before visiting a doctor. However, in no case should you engage in self-diagnosis and self-medication based on the data obtained: to correctly analyze the results and make a diagnosis, you must contact a specialist.

Organoleptic indicators

Volume . The total volume of fluid for analysis does not allow us to draw any conclusions about diuresis disorders. It is only necessary to determine the specific gravity of urine (relative density).

Diuresis is the volume of urine produced over a certain period of time (daily or minute diuresis). Daily diuresis is usually 1.5–2 liters (70–80% of the liquid drunk). An increase in daily diuresis is called polyuria, a decrease to 500 ml is called oliguria.

Color urine, as well as transparency, is determined by the laboratory assistant by eye. Normal color can vary from straw to deep yellow. It is determined by the presence of coloring substances in the urine - urobilin, urozein, uroerythrin. Any other shades can signal certain pathologies in the body, for example:

• dark brown – jaundice, hepatitis;
• red or pink color indicates the presence of blood in the analysis;
• dark red – hemoglobinuria, hemolytic crisis, porphyrin disease;
• black – alkaptonuria;
• a grayish-white color indicates the presence of pus;
• green or blue color is explained by rotting processes in the intestines.

Smell during a general urine analysis it is not decisive, since many foods containing essential oils or simply strong-smelling foods can give it a specific odor. However, some odors may indicate certain pathologies:

• the smell of ammonia indicates cystitis;
• fecal odor - E. coli;
• putrid odor – gangrenous processes in the urinary tract;
• the smell of acetone – ketonuria (the presence of ketone bodies in the urine);
• the smell of rotting fish – trimethylaminuria (accumulation of trimethylamine in the body).

Normally, the smell of urine is mild and somewhat specific. If the container is open, the smell becomes pungent due to the oxidation process.

Foaminess . Normally, when shaking urine, practically no foam forms in it, and if it does, it is transparent and unstable. If the foam persists or is stained, we can talk about jaundice or the presence of protein in the urine.

Transparency urine of a healthy person approaches absolute. Cloudiness can be caused by the presence of red blood cells, bacteria, mucus, fats, salts, pus and other substances. The presence of any substance is detected using special techniques (heating, adding various acids, etc.). If red blood cells, bacteria, protein or epithelium were detected in the urine, this indicates urolithiasis, pyelonephritis, prostatitis and some other diseases. White blood cells indicate cystitis. Precipitation of salts indicates the presence of urates, phosphates, and oxalates.

physical and chemical indicators

Density . The specific gravity of urine is an indicator that depends on age. The norm for adults and children over 12 years old is 1.010–1.022 g/l, for children 4–12 years old – 1.012–1.020, for children aged 2–3 years old – 1.010–1.017, newborns – 1.008–1.018. The density of urine depends on the amount of salts, proteins, sugars and other substances dissolved in it. In some pathologies, this indicator increases due to the presence of bacteria, leukocytes, and red blood cells. An increased rate may indicate diabetes mellitus or infectious processes in the urinary tract. In pregnant women - indicates toxicosis. Density may also be increased due to insufficient fluid intake or fluid loss. A reduced rate indicates renal failure and diabetes insipidus. It may also occur when drinking too much or taking diuretic medications.

Acidity Normally it is in the range of 4–7 pH. A reduced rate may indicate the presence of many diseases: chronic renal failure, increased levels of potassium in the blood, parathyroid hormones, ureaplasmosis, kidney or bladder cancer, etc. Increased acidity also occurs with dehydration and fasting, when taking certain medications, at high temperatures and heavy consumption of meat. A pH higher than normal may indicate diabetes mellitus, decreased potassium levels, and disturbances in the acid-base balance of the blood.

Biochemical characteristics

Protein . Its concentration normally should not exceed 0.033 g/l. Detection of elevated levels may indicate kidney damage, inflammation in the genitourinary system, allergic reactions, leukemia, epilepsy, and heart failure. An increase in the amount of protein occurs with increased physical activity, profuse sweating, and long walking.

Increased protein in the urine is detected in physically poorly developed children 7–16 years old and pregnant women.

Sugar (glucose) in urine at normal levels – no more than 0.8 mmol/l. Increased sugar can be a consequence of diabetes, excessive consumption of sweets, kidney problems, acute pancreatitis, Cushing's syndrome, increased adrenaline levels due to damage to the adrenal glands. Also, increased sugar levels in the urine can occur during pregnancy.

Bilirubin is a bile pigment that should normally be absent in urine. Its detection indicates a sharp increase in the concentration of bilirubin in the blood, which is why the kidneys take on the job of removing it (normally, bilirubin is completely eliminated through the intestines). An increased level of this pigment in the urine indicates cirrhosis of the liver, hepatitis, liver failure, and cholelithiasis. The cause may also be massive destruction of red blood cells in the blood due to hemolytic disease, sickle cell anemia, malaria, and toxic hemolysis.

Ketone bodies (acetone) Normally, they should not be detected in a general urine test. Their detection indicates metabolic disorders as a result of diseases such as diabetes mellitus, acute pancreatitis, thyrotoxicosis, and Itsenko-Cushing's disease. Also, the formation of ketone bodies occurs during fasting, due to alcohol intoxication, with excessive consumption of protein and fatty foods, due to toxicosis in pregnant women, as well as after injuries affecting the central nervous system.

Microscopic studies

Sediment (organic, inorganic) . In a general urine analysis, sediment refers to cells, cylinders, and salt crystals that settle after short-term centrifugation. We will talk in more detail about the various substances that can be detected in sediment below.

Blood cells (erythrocytes, leukocytes) . Erythrocytes - red blood cells - may be present in urine in small quantities (for women - 0-3 in the field of view, single ones - for men). An increased level of red blood cells indicates serious diseases, such as:

• urolithiasis disease;
• nephrotic syndrome;
• kidney infarction;
• acute glomerulonephritis;
• cancer of the kidney, bladder, prostate.

Leukocytes in the sediment, identified in a general urine test, may be a consequence of urinary tract diseases (pyelonephritis, cystitis, urolithiasis, prostatitis, urethritis, cystitis, etc.). Normally, leukocytes in the urine of women and children are 0–6 per field of view, and in men – 0–3.

If the results of a general urine test revealed an increased level of leukocytes, you should make an appointment with a urologist, who will probably prescribe additional tests - a repeat OAM or in combination with a urine test according to Nechiporenko, a three-glass test, or an ultrasound of the kidneys. Often, all concerns are dispelled after repeated and additional studies are carried out.

Hyaline casts - These are cylindrical formations, which are dominated by renal tubular cells and protein. Normally they should not be in the urine. Their detection (over 20 in 1 ml) indicates hypertension, pyelonephritis, glomerulonephritis. These cylindrical formations can also occur when taking diuretics.

Grainy cylinders . Their composition is dominated by erythrocytes and renal tubular cells. The presence of granular casts in the urine in any quantity indicates viral infections, pyelonephritis and glomerulonephritis. Lead poisoning is also possible.

Wax cylinders , or waxy casts, are formed as a result of a long stay in the lumen of the renal tubule of a hyaline or granular cast. Their presence in the urine in any quantity indicates pathologies such as chronic renal failure, renal amyloidosis (deposition of insoluble protein - amyloid) in the kidney tissue, nephrotic syndrome.

Bacteria . The presence of any bacteria in a general urine test indicates inflammatory processes in the urinary system. That is, normally bacteria should be absent. Their detection indicates infectious diseases such as urethritis, cystitis, prostatitis and others. For the results to be reliable, careful hygiene of the intimate areas is necessary before collecting urine.

Mushrooms in urine, which normally should not be detected, are the result of infectious fungal lesions of the urinary tract and external genitalia. In addition, their detection may indicate immunodeficiency states and long-term use of antibiotics.

Salts . Their absence in urine is normal, but their presence in sediment may indicate the possibility of kidney stones. Elevated levels of uric acid (urate) can be the result of gout, nephritis, and chronic renal failure. Urates are often the result of a certain diet and dehydration. In newborns, the presence of urate is normal. Oxalates can be formed due to diabetes mellitus and pyelonephritis, hippuric acid crystals - due to intestinal dysbiosis and liver failure, phosphates - due to high calcium levels in the urine. However, it is always worth remembering that the detection of certain salts is often associated with increased consumption of certain foods, which means their concentration can be easily reduced by changing the diet.

A summary table of the main indicators of a general urine test with normal values ​​is as follows:

So, with the help of a general urine test, you can identify a variety of kidney and bladder diseases, problems with the prostate gland, tumors and pyelonephritis, as well as a number of pathological conditions in the initial stages, when there are no clinical manifestations as such. Therefore, OAM should be performed not only when painful sensations appear, but also for the prevention and early detection of many diseases of the genitourinary system in order to prevent their further development.

Urine is not just a biological fluid, but also a kind of indicator that signals any changes occurring in the body. The main organ responsible for the production, excretion and composition of human urine is the kidneys. Urination or diuresis is the most important process, without which it is impossible to maintain the normal functioning of the body, because metabolic products, salts and toxins are eliminated along with urine.

What affects the composition of urine?

During the day, in an adult, the blood is cleansed by the kidneys about 300 times, after which waste is eliminated through the urethra. It is generally accepted that after filtration, 1.2 to 2 liters of liquid should be released. Its quantity and chemical and biological indicators are determined by a number of factors:

• climatic conditions,
• physical activity,
• age, weight,
• food consumed.

Any deviations from the norm (both more and less) are a reason to consult a doctor for additional examination.

In order for the tests to be reliable, it is recommended to adhere to the rules for collecting urine. The first morning portion, which is collected after thoroughly washing the external genitalia, is subject to study. The disposable container must be delivered to the laboratory within 2 hours, otherwise the chemical composition of the urine may change.

Physical properties of urine

The physical characteristics of urine include:

• Density or specific gravity (determined using a urometer). When drinking large volumes of water, the amount of urine increases and, accordingly, its density becomes less. The norm is in the range from 1.002 to 1.040 g/ml. After heavy sweating, the density may reach the upper limit norm, however, if this is associated with sports training, there is no need to worry.
• Acidity (pH). This indicator can change its value depending on the food consumed: plant foods increase, and meat products reduce the level of alkali in the urine. The average number is 5.5-7. High acidity is the first symptom of pyelonephritis, cystitis, thyroid dysfunction or kidney failure. An acid reaction is typical for newborns in the first days of life.
• Color and smell. As a rule, in healthy people, urine is colored moderately yellow and does not have a strong aroma. Density also affects color - the higher it is, the more pronounced the color pigment. If the urine has acquired a reddish tint, this is a possible sign of diseases such as glomerulonephritis or porphyria. Urine that is the color of dark beer indicates liver disease (hepatitis or jaundice). And urination with the smell of ammonia indicates an acute inflammatory process of the bladder (cystitis).

PLEASE NOTE: Eating foods such as beets or carrots, or taking certain medications (such as aspirin) the night before a test can affect the color of your urine.

What is included in urine?

The chemical composition of the urine of a healthy person is varied and inconsistent; in total, almost 150 different organic and inorganic compounds were found in this waste product.

The bulk of the total mass is occupied by urea (normally up to 35 g/day) - a product of the breakdown of proteins in the body. Urine is also considered normal if it contains substances such as:

• uric acid (up to 0.7 g), this compound can cause the formation of stones in the genitourinary system,
• creatinine (up to 36 mg),
• ammonia (up to 57),
• sulfates (up to 83 mg) and phosphates (up to 127 mg),
• as well as elements known in chemistry - sodium, potassium, magnesium and calcium.

Organic sediment

Secondary urine may contain bloody cells, leukocytes and epithelium, which together form an organic sediment.

Women contain from 1 to 3 red blood cells, and their presence in men is a clear sign of kidney or genitourinary system disease.

The normal white blood cell count should not exceed 7 for men and 10 for women. An increased level of leukocytes (from 60) is accompanied by cloudy urine, which acquires an unpleasant smell of rot and a greenish tint. If leukoceturia is bacterial in nature, this indicates a current infectious disease.

GOOD TO KNOW: When shaking the container, the urine should not foam. Foam formation occurs when there is protein or bile acid in the composition.

Pathological urine indicators

Urine should normally contain no components such as protein, blood, sugar and others. They are a pathology and signal certain disturbances in the functioning of the body.

For example, if laboratory diagnostics revealed a certain amount of glucose (over 10 g), this is an indicator of glycosuria, which is a symptom of diabetes mellitus. Also, in this case, one should not exclude diseases of the kidneys, liver and pancreas.

USEFUL TO KNOW: For reliable results of testing urine for sugar, it is collected within 24 hours, skipping the first urination.

In case of acute inflammation of the genitourinary system, red blood cells (blood cells) may be present in the urine. This pathology is sometimes observed in athletes after injuries to the urinary organs.

If a lot of ketone bodies come out along with urine, this means that the body uses fat reserves instead of carbohydrates to produce energy. This phenomenon can be observed with diabetes, grueling physical training and fasting.

Inflammatory processes are also indicated by cylinders or cubic particles of epithelium, which are normally absent in human urine.

With kidney or heart disease, the patient may experience proteinuria - an increase in the amount of protein in the urine. This substance is almost always associated with disorders of the body. In adults, the amount of protein should not exceed 0.033 g/l, and in infants - from 30 to 50 mg. Sometimes this indicator is increased under the influence of elevated temperature or after physical exertion. If repeated tests detect protein in the urine in the amount of:

• 150-500 mg/day – this indicates the development of nephritis, uropathy, acute or chronic glomerulonephritis,
• 500-2000 mg – possible manifestation of post-streptococcal glomerulonephritis in the acute stage,
• over 2000 mg – the patient has non-rotic syndrome.

Components such as bilirubin and urobilinogen should not be present in the analysis. They usually turn the urine a rich yellow or brown color and indicate problems with the liver or gallbladder.

So, the composition of urine, as well as its physicochemical properties, can change under the influence of various diseases. In any case, only a doctor should make the correct diagnosis. It is worth regularly monitoring any changes in the urine - this will help to promptly detect and prevent disturbances in the body’s functioning.