The human urinary system is designed to remove metabolic products. The main role of filtration is performed by the kidneys. In any case, the body will be cleansed of harmful or processed unnecessary substances accumulated in the filter, regardless of the amount of liquid consumed. But the density of urine depends on how much water a person drinks. In medicine, it is called the specific gravity of urinary secretions. Why analyzes are carried out to determine this value?

General studies of urine for relative density show how much the kidneys are able to concentrate and dilute it. This indicator should normally be 1.005-1.028 units. But the numbers change depending on the time of day, as people's metabolism and the amount of water consumed per day fluctuate constantly. Basically, the specific gravity of urine depends on the following factors:

• Profuse sweating;
• High body or environmental temperature;
• The amount of water you drink;
• Eating food that negatively affects metabolic processes (salty, fried, fatty);
• Respiratory rate (this also releases fluid from the body).

Decreased urine density in children at birth will not fall below 1.010. But with age, the indicators gradually increase, and the proportion equals the norms of mature people.

To study the functionality of the urinary system, morning sampling is performed. It will be the most informative, since at night a person’s breathing is slow, water does not enter, and sweating decreases.

Indicators above the norm: why does the specific gravity of urine increase?

Hyperstenuria occurs with certain pathologies in the human body. As a rule, it is accompanied by tissue swelling (lower limbs, eyelids), which gradually increases and intensifies.

What diseases or disorders cause urine tests to be higher than normal?

• Fluid loss (strong sweating, vomiting, burns, massive bleeding);
• Intestinal obstruction;
• Dysfunction of the urinary organs (glomerulonephritis, renal failure, nephrotic syndrome);
• Toxic effect from prolonged use of antibacterial agents;
• Toxicosis in women due to pregnancy;
• Endocrine system disorders (hormonal failure, diabetes mellitus);
• Abdominal injury;
• Water retention in the body.

Hyperstenuria caused by physiological factors does not require treatment. It will pass on its own as soon as the patient's health, metabolism and sufficient water supply are restored. But with pathological changes, such as dysfunction of the endocrine and urinary systems, it is necessary to prescribe therapeutic agents.

How to understand that a person has an increased specific gravity of urinary secretions? To do this, you need to assess the state of health and analyze the disturbing symptoms. For example, hyperstenuria provokes not only swelling, but also back pain. Urine becomes dark, its amount decreases, acquires an unpleasant odor. Changes affect the general condition, a person quickly gets tired, he wants to sleep.

It is important to note that in children, numbers that exceed the norm of the specific gravity are more often caused by congenital or acquired diseases of the urinary organs. They are also associated with intestinal infections and reduced immunity.

Indicators below normal: why does urine lose density?

After an increase in the amount of fluid consumed, hypostenuria occurs. This often happens if the patient has had an infectious disease of the gastrointestinal tract and has experienced prolonged vomiting or diarrhea. Doctors recommend replenishing its reserves, which helps dilute urine. Then the indicators fall below the norm. The use of diuretics also affects physiological weight loss.

Pathological abnormalities include the following diseases:

• Diabetes insipidus, without therapy, leads to permanent dehydration (it can be neurogenic, nephrogenic, of nervous origin, in pregnant women);
• Chronic disorders of the urinary organs;
• Acute pyelonephritis;
• Chronic renal failure.

With a decrease in indicators to 1.010, doctors can already refer the patient for kidney diagnostics. Thus, at an early stage in the development of pathology, it is possible to eliminate the problem and prevent serious changes in vital organs.

Urinalysis: how is it done?

Urinary secretions are products of metabolic processes. They are formed from blood that is filtered by the kidneys. The aqueous electrolyte solution (92-99% water) contains organic particles. It has many components. Every day, the kidney filters excrete urea and salts from the body.

Urinalysis diagnoses the functionality of the kidneys and the whole organism. It also helps to evaluate the effectiveness of already prescribed therapy. Why? Because the metabolic processes that affect the specific gravity of urine go through several stages:

1. The constituent elements of the blood are filtered, so the primary urine is similar to plasma, but contains macroparticles (glycogen, protein, fat).
2. Reabsorption takes place in the tubules. That is, nutrients are absorbed back into the bloodstream.
3. The residual fluid forms secondary urine. It is just excreted by urination.

To determine the weight of urinary secretions in adults or children, a urometer is used. But to assess kidney function, tests are carried out:

• Zimnitsky;

The analysis checks the activity of renal function in men / women who do not change their drinking regimen. Collect secretions every 3 hours. So per day should be 8 images of urine. Using a urometer, the average value of the indicators is determined. Normally, the value of nighttime diuresis is 30% different from daytime.

• concentration;

In this case, patients change the drinking regimen, removing completely the consumption of any liquid per day. To avoid feelings of hunger, they are given protein food. If the patient does not tolerate the regimen, then they are allowed to drink some water. Collect urine after 4 hours. Look at the specific gravity data: if it is at the level of 1.015 or drops to 1.010, then the kidney filters do not cope well with the concentration of secretions.

The relative density of urine and its shade: what are they talking about?

Evaluation of the properties of urine includes not only the diagnosis of its weight. Always take into account the shade of urinary secretions. And it depends on the presence of various components in the urine. What affects its color can be seen from the table.

The intensity varies from the specific gravity and volume of secretions. Often, the color is affected by the use of medications that color it in a certain shade.

An underestimated relative density always discolors its shade. As mentioned above, most often it manifests itself in diabetes insipidus of various origins. Consider the most common forms.

1. Neurogenic.

Occurs when there is insufficient production of antidiuretic hormone. Filters become unable to hold water, so even without fluid intake, diuresis continues until the body is completely dehydrated. Urine readings drop to 1.005.

The mechanism of development of the neurogenic form depends on the dysfunction of the pituitary / hypothalamus. It reduces or completely stops the production of tropic and antidiuretic hormones. The reason for this condition is not always clear. Therefore, patients are diagnosed with the idiopathic type, moreover, it affects young people who have reached adulthood. Another factor of violations is a head injury, a tumor or a surgical intervention that injures the listed areas of the brain.

1. Nephrogenic.

Occurs with the appearance of parenchymal kidney diseases and their chronic insufficiency. In turn, nephrogenic disorders provoke various metabolic dysfunctions.

• Conn's syndrome. At the same time, pressure rises, muscle fibers weaken.
• Hyperparathyroidism. Affects bones, contributes to the development of osteoporosis and nephrocalcinosis. A lot of calcium is found in the secretions, they become white in color.

Very rarely, nephrogenic diabetes insipidus is congenital, usually it is acquired in the course of life.

In order to identify such serious disorders in the urinary system and in the body as a whole at an early stage, healthy people are recommended to be tested twice a year. In the presence of diseases, the diagnosis is carried out in the course of treatment and periodically in the direction of a doctor.

Urine is an aqueous solution of electrolytes and organic matter. The main component of urine is water (92-99%), in which about a thousand different components are dissolved, many of which have not yet been fully described. Approximately 50–70 dry substances are removed from the body with urine every day, most of which are urea and sodium chloride. The composition of urine varies considerably even in healthy people.

Typically, the analysis is prescribed:

In diseases of the urinary system,

For examination during preventive examinations,

To assess the course of the disease, control the development of complications and the effectiveness of the treatment.

Persons who have had a streptococcal infection (tonsillitis, scarlet fever) are advised to take a urine test 1-2 weeks after recovery. Healthy people are recommended to perform this analysis 1-2 times a year.

On the eve, it is better not to eat vegetables and fruits that can change the color of urine (beets, carrots), do not take diuretics. Before collecting urine, it is necessary to make a hygienic toilet of the genital organs. Women are not recommended to take a urine test during menstruation. For the correct conduct of urine sampling, it is necessary to release a small amount of urine into the toilet during the first morning urination, and then, without interrupting urination, substitute a container for collecting urine, in which to collect about 100-150 ml of urine. Urine collection utensils for analysis should be clean and dry. In poorly washed dishes, urine quickly becomes cloudy and acquires an alkaline reaction. Long-term storage of urine leads to a change in its physical properties, the multiplication of bacteria and the destruction of sediment elements.

Norms in the results:

The amount of urine delivered has no diagnostic value,

Colour: various shades of yellow,

Transparency: transparent,

Smell: unsharp, non-specific,

pH reaction: acidic, pH less than 7,

Glucose: absent

Ketone bodies: none

Bilirubin: absent

Erythrocytes: 0-3 in the field of view for women, 0-1 in the field of view for men,

Leukocytes: 0-6 in the field of view for women, 0-3 in the field of view for men,

Protein: absent

Epithelium: 0–10 per field of view,

Cylinders: none

Salts: none

Bacteria: absent.

Normal urine has a straw-yellow color of varying intensity. The color of urine in healthy people is determined by the presence of substances formed from blood pigments. The color changes depending on its relative density, daily volume and the presence of various coloring components that enter the human body with food, drugs, vitamins.

Color changes not caused by a disease:

Pink - from acetylsalicylic acid, carrots, beets,

Brown - taking bear ears, sulfonamides, activated charcoal,

Greenish-yellow - from rhubarb, Alexandrine leaf,

Saturated yellow - taking riboflavin, 5-NOC, furagin,

After heavy drinking - colorless. It is not a pathology unless it is a permanent symptom.

Normally, the more intense the yellow color of urine, the higher its relative density, and vice versa. Concentrated urine has a brighter color.

Color changes in diseases:

With pathology of the liver and gallbladder - the color of strong tea,

With glomerulonephritis - a reddish tint, the color of "meat slops",

If the urine is consistently colorless or slightly yellow, this is a symptom of advanced kidney disease.

A sandy sediment, if you pour urine into a jar, indicates a tendency to form kidney stones.

With inflammation of the urinary tract (urethritis, cystitis, pyelonephritis) - with flakes, cloudy,

Foamy - this occurs only in men. This means that semen has entered the urinary tract. This happens after sex, wet dreams and with an excess of seminal fluid.

Normal fresh urine is clear. A small cloud of turbidity may appear in it due to epithelial cells and mucus. Severe turbidity of urine can be caused by the presence of erythrocytes, leukocytes, fat, epithelium, bacteria, a significant amount of various salts (urates, phosphates, oxalates) in it. The causes of turbidity are clarified by microscopy of the sediment and by chemical analysis.

Slightly cloudy urine is often observed in older people (mainly from the urethra). The resulting turbidity of urine when standing in the cold usually depends on the precipitation of urates, in heat - phosphates.

Urine specific gravity measures the ability of the kidneys to concentrate and dilute urine. The decrease in the concentration ability of the kidneys occurs simultaneously with the decrease in other renal functions.

Normally functioning kidneys are characterized by wide fluctuations in the specific gravity of urine during the day, which is associated with the intake of food, water and fluid loss by the body (sweating, breathing). The kidneys under various conditions can excrete urine with a relative density of 1001 to 1040.

Distinguish:

Hypostenuria (specific gravity below 1010),

Isosthenuria (the appearance of a monotonous specific gravity, corresponding to that of primary urine 1010),

Hyperstenuria (high specific gravity).

The maximum upper limit of the specific gravity of urine in healthy people is 1028, in children under 3-4 years old - 1025. A lower specific gravity is a sign of a violation of the concentration ability of the kidneys. It is generally accepted that the minimum lower limit of the specific gravity of urine, which is 1003–1004, indicates normal kidney function.

Specific gravity can be increased with: oliguria (reduced urine output); toxicosis of pregnant women; large loss of fluid (prolonged vomiting, diarrhea); low fluid intake; intravenous infusion of mannitol, dextran, radiopaque agents; the presence of drugs or their decay products in the urine; glomerulonephritis, nephrotic syndrome; uncontrolled diabetes mellitus (with the release of glucose in the urine); heart failure, accompanied by edema; liver diseases; adrenal insufficiency.

The specific gravity can be lowered in: diabetes insipidus; chronic renal failure; acute damage to the renal tubules; polyuria - profuse urination (taking diuretics, drinking plenty of water).

The kidneys excrete unnecessary substances from the body and retain the necessary substances to ensure the exchange of water, electrolytes, glucose, amino acids and maintain acid-base balance. The reaction of urine (pH) largely determines the effectiveness and characteristics of these mechanisms. Normally, the urine reaction is most often slightly acidic (pH 5.0–7.0). It depends on many factors: age, diet, body temperature, physical activity, kidney condition, etc. The lowest pH values ​​in the morning on an empty stomach, the highest after eating. When eating predominantly meat food, the reaction is more acidic, when eating vegetable food, it is alkaline.

When standing urine, the pH increases due to the formation of ammonium by microorganisms (pH 9 indicates incorrect sample preservation). Constant pH values ​​(7–8) suggest the presence of a urinary tract infection. Changes in the pH of urine depend on the pH of the blood: with acidosis, the urine is acidic, with alkalosis, it is alkaline. The discrepancy between these indicators occurs with chronic lesions of the tubules of the kidneys: hyperchloric acidosis is observed in the blood, and the reaction of the urine is alkaline.

It is important to determine the pH at:

Urolithiasis (urine reaction determines the possibility and nature of stone formation: uric acid stones are more often formed at pH below 5.5, oxalate stones at 5.5–6.0, phosphate at pH 7.0–7.8),

Specific diet (high and low potassium, sodium, phosphate),

Pathologies of the endocrine system,

kidney disease,

Treatment with diuretics.

pH rises (pH> 7): after eating with a vegetarian diet; with hyperkalemia (high levels of potassium in the blood); chronic renal failure; hyperfunction of the parathyroid gland; prolonged vomiting; tumors of the genitourinary system; some specific conditions; as a result of the action of sodium citrate, bicarbonates, adrenaline, aldosterone.

pH decreases (pH< 5): при диете с высоким содержанием мясного белка, клюквы; голодании; гипокалиемии (низкое содержание калия в крови); обезвоживании; лихорадке; сахарном диабете; туберкулезе; сильной диарее; в результате действия аскорбиновой кислоты, кортикотропина, хлорида аммония, метионина.

Protein is normally absent in the urine or there are small traces of it, since the protein molecules are large and not always able to pass through the membrane of the renal glomeruli.

The appearance of protein in the urine (proteinuria) can be:

Physiological (orthostatic, hypothermia, after increased physical activity);

Pathological (for various diseases).

In the renal glomeruli, about 5 g of protein, mainly albumin, is filtered per day. More than 99% of it enters the blood again, less than 100 mg / day is removed from the urine. Physiological proteinuria is characterized by a protein content lower than 0.3 g / l.

Proteinuria is a common nonspecific symptom of kidney disease. There are non-massive (loss up to 3 g/day) and massive (over 3 g/day) proteinuria. In renal proteinuria, protein is found in both daytime and nighttime urine. Proteinuria is often combined with the appearance in the urine of cylinders, erythrocytes, leukocytes.

Proteinuria can manifest itself in: acute and chronic glomerulonephritis; acute and chronic pyelonephritis; inflammatory diseases of the urinary tract (cystitis, urethritis); nephropathy of pregnant women; diseases with high temperature; severe heart failure; kidney tuberculosis; hemorrhagic diseases; nephritis caused by taking analgin and similar substances; hypertension; tumors of the urinary tract; some specific diseases.

Normally, there is no sugar in the urine, since all glucose after filtering through the membrane of the glomeruli of the kidneys is completely absorbed back into the tubules.

The appearance of glucose (glucosuria) can be:

Physiological (with stress, taking increased amounts of carbohydrates in the elderly),

Extrarenal (diabetes mellitus, pancreatitis, diffuse liver damage, hyperthyroidism, traumatic brain injury, stroke, carbon monoxide poisoning, morphine, chloroform and other diseases),

Renal (renal diabetes, chronic nephritis, acute renal failure, pregnancy, phosphorus poisoning, certain drugs).

When the concentration of glucose in the blood is more than 8.8–9.9 mmol / l, sugar appears in the urine.

Possible reasons for the appearance of glucose in the urine: intake of large amounts of carbohydrates with food; pregnancy; burns, severe injuries; myocardial infarction; poisoning with strychnine, morphine, phosphorus; steroid, renal diabetes; hyperthyroidism (pathology of the thyroid gland); acute pancreatitis; diabetes; some specific diseases.

Bilirubin is normally absent in the urine. It is formed during the destruction of hemoglobin, about 250-350 mg / day. With an increase in the concentration of bilirubin in the blood, it begins to be excreted by the kidneys and is found in the urine (bilirubinemia).

Causes of bilirubinemia:

- increased breakdown of hemoglobin (hemolytic anemia, polycythemia, resorption of massive hematomas); obstructive jaundice, liver infections, liver dysfunction (viral hepatitis, chronic hepatitis, cirrhosis of the liver); the result of the action of toxic substances (alcohol, organic compounds, infectious toxins); secondary liver failure (due to heart failure, liver tumors); increase in the formation of stercobilinogen in the gastrointestinal tract (ileitis, colitis, intestinal obstruction).

Ketone bodies include acetone, acetoacetic and beta-hydroxybutyric acids. In a healthy person, 20–30 mg of ketones are excreted in the urine per day. An increase in the excretion of ketones in the urine (ketonuria) appears when there is a violation of carbohydrate, fat or protein metabolism.

Primary ketonuria: diabetes mellitus; coma and precomatose states; alcoholic ketoacidosis (refusal of food for 2-3 days while taking alcohol); acute pancreatitis.

Secondary ketonuria: acetemic vomiting in young children (with infectious diseases, carbohydrate starvation, etc.); unbalanced diet (prolonged fasting; a diet aimed at reducing body weight; eating predominantly protein and fatty foods; excluding carbohydrates from the diet); postoperative (with extensive mechanical muscle injuries (crash syndrome); after operations on the meninges, craniocerebral injuries, subarachnoid hemorrhages, severe irritation and excitation of the central nervous system); glycogen disease; thyrotoxicosis; Itsenko-Cushing's disease; hyperproduction of corticosteroids (tumor of the anterior pituitary gland or adrenal glands).

In the urinary sediment, organized sediment (cellular elements, cylinders, mucus, bacteria, yeast fungi) and unorganized (crystalline elements) are distinguished.

With urine, 2 million erythrocytes are excreted per day, which, in the study of urine sediment, is normally less than 3 erythrocytes per field of view for women and 1 erythrocyte per field of view for men. Anything above is hematuria.

Allocate:

Gross hematuria (when the color of urine is changed);

Microhematuria (when the color of urine is not changed, and red blood cells are found only under a microscope).

In the urinary sediment, erythrocytes can be unchanged (containing hemoglobin) and altered (devoid of hemoglobin, leached). The appearance of leached erythrocytes in the urine is important for establishing the diagnosis of the disease, since they are most often of renal origin and are found in glomerulonephritis, tuberculosis and other kidney diseases. Fresh unchanged erythrocytes are more common for urinary tract lesions (urolithiasis, cystitis, urethritis).

To determine the source of hematuria, a “three-vessel” test is used: the patient collects urine sequentially into three vessels. With bleeding from the urethra, hematuria is greatest in the first portion (unchanged erythrocytes), from the bladder - in the last portion (unchanged erythrocytes), with other sources of bleeding, erythrocytes are distributed evenly over all three portions.

Reasons for the appearance of red blood cells in the urine (hematuria): urolithiasis; tumors of the genitourinary system; glomerulonephritis; pyelonephritis; infectious diseases of the urinary tract (cystitis, tuberculosis); hemorrhagic diathesis (hemophilia, thrombocytopenia, thrombocytopathy, clotting disorder, intolerance to anticoagulant therapy); kidney injury; systemic lupus erythematosus (lupus nephritis); arterial hypertension; poisoning with derivatives of benzene, aniline, snake venom, anticoagulants, poisonous mushrooms.

Leukocytes in the urine of a healthy person are contained in a small amount (in men 0-3, in women and children 0-6 leukocytes in the field of view). An increase in the number of leukocytes in the urine (leukocyturia) indicates inflammatory processes in the kidneys (pyelonephritis) or urinary tract (cystitis, urethritis). To establish the source of leukocyturia, a three-glass test is used: the predominance of leukocytes in the first portion indicates urethritis or prostatitis, in the third - cystitis, a uniform distribution of leukocytes in all portions can most likely indicate kidney damage.

The so-called sterile leukocyturia is possible. This is the presence of leukocytes in the urine in the absence of bacteriuria and dysuria (with exacerbation of chronic glomerulonephritis, contamination during urine collection, condition after antibiotic treatment, bladder tumors, kidney tuberculosis, interstitial analgesic nephritis).

Causes of leukocyturia: acute and chronic glomerulonephritis, pyelonephritis; cystitis, urethritis, prostatitis; stones in the ureter; tubulointerstitial nephritis; systemic lupus erythematosus.

Epithelial cells are almost always found in the urinary sediment. Normally, there are no more than 10 of them in the field of view.

An increase in the number of squamous cells usually indicates an incorrect preparation of the patient for the collection of analysis.

An increase in the number of transitional epithelial cells indicates: intoxication; fever intolerance to anesthesia, drugs, after operations; jaundice of various origins; urolithiasis (at the time of passage of the stone); chronic cystitis; bladder polyposis; bladder cancer.

The appearance of cells of the renal epithelium is possible with: pyelonephritis; intoxication (taking salicylates, cortisone, phenacetin, bismuth preparations, poisoning with salts of heavy metals, ethylene glycol); tubular necrosis; kidney transplant rejection; nephrosclerosis.

A cylinder is a protein coagulated in the lumen of the renal tubules and includes any contents of the lumen of the tubules. The cylinders take the shape of the tubules themselves (cylindrical impression). In the urine of a healthy person, single cylinders in the field of view can be detected per day. Normally, there are no cylinders in the general analysis of urine. The appearance of cylinders (cylindruria) is a symptom of kidney damage. The type of cylinders (hyaline, granular, pigmented, epithelial, etc.) has no special diagnostic value.

Cylinders (cylindruria) appear in the general analysis of urine with: a wide variety of kidney diseases; infectious hepatitis; scarlet fever; systemic lupus erythematosus; osteomyelitis.

Normally, the urine in the bladder is sterile. When urinating, microbes from the lower urethra enter it, but their number is not more than 10,000 in 1 ml. Bacteriuria refers to the detection of more than one bacterium in the field of view (qualitative method), or the growth of colonies in culture, exceeding 100,000 bacteria per 1 ml (quantitative method).

The presence of bacteria in the urine in the absence of complaints is regarded as asymptomatic bacteriuria. A similar condition often occurs with organic changes in the urinary tract; in women who are promiscuous; in older people. Asymptomatic bacteriuria increases the risk of urinary tract infection, especially during pregnancy (infection develops in 40% of cases).

The detection of bacteria in the analysis of urine indicates an infectious lesion of the organs of the urinary system (pyelonephritis, urethritis, cystitis, etc.). It is possible to determine the type of bacteria only with the help of bacteriological research.

The detection of yeast of the genus Candida indicates candidiasis, which occurs most often as a result of improper antibiotic therapy, the use of immunosuppressants, and cytostatics.

Determination of the type of fungus is possible only with bacteriological examination.

Mucus is secreted by the epithelium of the mucous membranes. Normally absent or present in the urine in small quantities. With inflammatory processes in the lower urinary tract, the content of mucus in the urine increases. An increased amount of mucus in the urine may indicate a violation of the rules for preparing for taking an analysis.

Urine is a solution of various salts that can precipitate (form crystals) when the urine is standing. The formation of crystals is facilitated by low temperature. The presence of certain salt crystals in the urinary sediment indicates a change in the reaction to the acidic or alkaline side. Excessive salt content in the urine contributes to the formation of stones and the development of urolithiasis.

Uric acid and its salts (urates) appear with: highly concentrated urine; acid reaction of urine (after exercise, with a meat diet, fever, leukemia); uric acid diathesis, gout; chronic renal failure; acute and chronic nephritis; dehydration (vomiting, diarrhea, fever); severe inflammatory-necrotic processes; tumors; leukemia; cytostatic therapy; lead poisoning; in newborns.

Hippuric acid crystals: eating fruits containing benzoic acid (blueberries, lingonberries); diabetes; liver disease; putrefactive processes in the intestines.

Tripelphosphates, amorphous phosphates: alkaline urine reaction in healthy people; vomiting, gastric lavage; cystitis; hyperparathyroidism.

calcium oxalate (oxaluria occurs with any urine reaction): eating foods rich in oxalic acid (spinach, sorrel, tomatoes, asparagus, rhubarb, potatoes, tomatoes, cabbage, apples, oranges, strong broths, cocoa, strong tea, excessive consumption of sugar, mineral water with a high content of carbon dioxide and salts of organic acids); severe infectious diseases; pyelonephritis; diabetes; ethylene glycol poisoning; oxalosis or primary hyperoxalaturia (genetic deficiency).

Neutral Phosphate Lime: arthritis and arthrosis of rheumatic etiology; Iron-deficiency anemia; chlorosis.

Leucine and Tyrosine: severe metabolic disorder; phosphorus poisoning; destructive liver diseases; pernicious anemia; leukemia.

Cystine: congenital disorder of cystine metabolism - cystinosis; cirrhosis of the liver; viral hepatitis; state of hepatic coma; Wilson's disease (congenital defect of copper metabolism).

Urinalysis according to Nechiporenko is a laboratory study of urine, with the help of which a doctor can assess the condition, function of the kidneys and urinary tract.

Urinalysis Nechiporenko is usually prescribed after a general urinalysis, if abnormalities were detected in the clinical analysis. Urine analysis according to Nichiporenko allows you to study these disorders in more detail for a correct diagnosis. With this analysis, the doctor can also monitor the effectiveness of the treatment.

After a thorough toilet of the genital organs, an average portion of urine is collected: for this, the first amount of excreted urine (15–20 milliliters) is passed, and the average portion of morning urine is placed in a prepared clean dish.

To conduct a urine test according to Nechiporenko, 1 ml is used from the portion of urine given by the patient and the number of urine components (per 1 ml) is counted: erythrocytes, leukocytes and cylinders.

The norms of urine analysis Nechiporenko:

- erythrocytes - no more than 1000; leukocytes - no more than 2000; cylinders - no more than 20.

An increase in certain uniform elements can confirm or refute the results of a general urinalysis. The conducted studies provide the maximum accuracy of the diagnosis.

To calculate the formed elements in a daily amount according to the Kakovsky-Addis method, fluid intake is limited during the examination period: the patient should not drink at night and drink less during the day. At the same time, the relative density of urine (1020–1025) and its pH (5.5) are standardized, which is very important for this analysis. Urine is collected for 10-12 hours. The patient urinates before going to bed (this portion of urine is poured out), marks the time, and after 10-12 hours urinates into the prepared dishes. This portion of urine is delivered to the laboratory for analysis. If it is impossible to hold urination for 10-12 hours, the patient urinates into the prepared dishes in several doses and notes the time of the last urination.

The Kakovsky-Addis number for normal urine is up to 1,000,000 for erythrocytes, up to 2,000,000 for leukocytes, and up to 20,000 for cylinders.

A urine sample according to Zimnitsky allows you to evaluate the concentration function of the kidneys (that is, the ability of the kidneys to concentrate and dilute urine).

The following indicators are evaluated in the laboratory:

The amount of urine in each of the 3-hour portions; relative density of urine in each portion,

Daily diuresis (total amount of urine excreted per day); diurnal diuresis (urine volume from 6 a.m. to 6 p.m. (1-4 servings)); nocturnal diuresis (urine volume from 18 pm to 6 am (5-8 portions)).

It is necessary to exclude the use of diuretics on the day of the study. The test is carried out with the usual drinking regimen and nutrition of the patient, no preliminary preparation is required, but it is advisable to warn the patient that it is desirable that the amount of fluid on this day does not exceed 1–1.5 liters. Violation of these conditions leads to an artificial increase in the amount of urine discharge (polyuria) and a decrease in its relative density, which makes it impossible to correctly interpret the results of the study. For the same reason, the Zimnitsky test is not advisable in patients with diabetes insipidus and diencephalic disorders (derived from the pathology of the diencephalon).

On the day of the study, it is also necessary to measure the daily amount of fluid drunk and in food (this information will be needed by the attending physician to interpret the result).

For the Zimnitsky test, 8 portions of urine are collected per day. At 6 o'clock in the morning the patient empties the bladder (this portion is poured out). Then, starting at 9 a.m., exactly every 3 hours, collects 8 portions of urine in separate jars (until 6 a.m. the next day). The time of collection of urine is marked on each jar. All portions are delivered to the laboratory.

Normally, in an adult, fluctuations in the volume of urine in individual portions range from 40 to 300 ml; fluctuations in the relative density of urine between the maximum and minimum values ​​​​should be at least 0.012-0.016 (for example, from 1008 to 1025 or from 1010 to 1026, etc.).

Normal concentration function of the kidneys is characterized by the ability to increase during the day the relative density of urine to maximum values ​​(over 1020), and the normal ability to dilute - the ability to reduce the relative density of urine below the osmotic concentration (osmolarity) of protein-free plasma, equal to 1010-1012.

In pathology, both a decrease in the concentration function of the kidneys and a violation of their ability to dilute urine can occur. Violation of the ability of the kidneys to concentrate urine is manifested by a decrease in the maximum values ​​of the relative density, while in none of the portions of urine during the Zimnitsky test, including at night, the relative density does not exceed 1020 (hypostenuria). At the same time, the ability of the kidneys to dilute urine is preserved for a long time, so the minimum relative density of urine can reach, as in the norm, 1005.

A decrease in the concentration ability of the kidneys leads to a decrease in the relative density of urine (hypostenuria) and an increase in the amount of urine (polyuria).

The low density of urine and its small fluctuations during the day may depend on extrarenal factors:

In the presence of edema, fluctuations in density can be reduced;

With prolonged adherence to a protein-free and salt-free diet, urine density can also remain low during the day;

Low density of urine with small fluctuations (1000–1001), with rare rises up to 1003–1004, is observed in diabetes insipidus.

Much less frequently in the clinic, there is an increase in the relative density of urine, which is detected during the Zimnitsky test. The reasons for this increase are: pathological condition, accompanied by a decrease in renal perfusion while maintaining the concentration ability of the kidneys (congestive heart failure, the initial stages of acute glomerulonephritis), etc.; diseases and syndromes accompanied by severe proteinuria (nephrotic syndrome); conditions associated with fluid loss; diabetes mellitus with severe glucosuria; toxicosis of pregnant women.

When examining this method, the patient limits fluid intake during the day and excludes it at night. Urine is collected for 3 hours. In the morning, the patient empties the bladder (this urine is discarded), notes the time, and exactly 3 hours later collects urine for examination.

The Ambourger method refers to methods for the quantitative determination of formed elements in urine. This determines the number of formed elements excreted in the urine in 1 minute.

Normally, the number of leukocytes in the minute volume of urine is 2000, erythrocytes - 1000. Sometimes in the literature you can find other numbers of the norm: leukocytes in the minute volume of urine - 2500, erythrocytes - 2000.

The patient collects urine for 24 hours, observing the usual drinking regimen. In the morning at 6–8 o’clock, he empties the bladder and notes the time (this portion of urine is poured out), and then during the day they collect all the urine in a clean, wide-mouthed vessel with a capacity of at least 2 liters, with a tightly closed lid. The last portion is taken exactly at the same time when the collection was started the day before (the start and end times of the collection are noted). If not all urine is sent to the laboratory, then the amount of daily urine is measured with a measuring cylinder, a part is poured into a clean container in which it is delivered to the laboratory, and the volume of daily urine is necessarily indicated.

On these days, the amount of liquid drunk in all forms must be taken into account (including fruits: watermelons, grapes, apples, etc.). In a healthy person, approximately 3/4 (65–80%) of the liquid drunk is normally excreted during the day.

Polyuria is an abundant separation of urine (more than 2000 ml per day). It can be due to many reasons:

Large amount of liquid drunk;

The use of osmotic diuretics (mannitol, urea, 40% glucose solution, albumin, etc.) or saluretics (thiazide derivatives, furosemide, uregit);

Severe impairment of kidney function;

Other diseases: diabetes insipidus, pyelonephritis.

Oliguria is a decrease in the amount of urine excreted per day. It can be caused both by extrarenal causes (limitation of fluid intake, increased sweating, profuse diarrhea, indomitable vomiting, fluid retention in the body in patients with heart failure), and impaired renal function in patients with glomerulonephritis, pyelonephritis, uremia, etc.

Anuria is a sharp decrease (up to 200–300 ml per day or less) or a complete cessation of urine output. There are two types:

Secretory anuria can be observed in shock, acute blood loss, uremia.

Excretory anuria is associated with a violation of the separation of urine through the urethra or with a decrease in bladder function with preserved kidney function.

Also in the daily analysis of urine, the ratio of daytime urine output to nighttime is determined. Normally, in a healthy person, there is approximately a twofold predominance of daytime diuresis over nighttime.

Nocturia is the equality or even the predominance of nocturnal diuresis over daytime. Nocturia is also an important indicator of a decrease in the concentration function of the kidneys, although it can also be due to other pathological conditions (heart failure, diabetes insipidus, etc.).

Urine for these tests is collected according to one scheme.

Urine is collected during the day: the first morning portion of urine is removed, all subsequent portions of urine allocated during the day, night and the morning portion of the next day are collected in one container, which is stored in the refrigerator (from +4 to +8 ° C) for the entire collection time (this is a necessary condition, since at room temperature the glucose content is significantly reduced). After completing the collection of urine, the contents of the container must be accurately measured, be sure to mix and immediately pour into a sterile container. Bring this container to the laboratory for testing.

You don't have to bring all the urine. It is necessary to indicate the daily volume of urine (diuresis) in milliliters, also write the height and weight of the patient.

This analysis refers to samples that evaluate the cleansing ability of the kidneys. Therefore, a decrease in the excretion of creatinine in the urine and an increase in its concentration in the blood indicate a decrease in filtration in the kidneys. After age 40, glomerular filtration decreases by 1% annually. Since the minute volume of filtration in the kidneys depends on the height and weight of a person, in order to normalize the indicator in people who deviate significantly in size from the average values, creatinine clearance is recalculated to the conditional value of the standard average body surface (1.7 m 2). To do this, you need to know the height and weight of a person. This is especially significant when conducting the Reberg test in children, since the corresponding age values ​​are given in terms of the standard body surface.

The analysis is carried out:

To control kidney function,

To assess the impact of heavy physical exertion; with endocrine diseases (diabetes, diseases of the thyroid gland, pituitary gland, adrenal glands).

In preparation for the study, it is necessary to avoid physical exertion, exclude strong tea, coffee, alcohol, observe the usual water regime, and limit the intake of meat food. It should be borne in mind that taking corticotropin, cortisol, thyroxine, methylprednisolone, furosemide and other drugs can affect the amount of filtration, so you should discuss the conditions for the test with your doctor in advance.

Simultaneously with the delivery of urine (at the end of the collection period), you need to take a blood sample to determine the concentration of creatinine in it.

Creatinine norms (ml / min / 1.7 m 2):

Children under 1 year old

65–100 ml / min / 1.7 m 2;

Men

1–30 years old 88–146 ml / min / 1.7 m 2;

30-40 years old 82-140 ml / min / 1.7 m 2;

40-50 years old 75-133 ml / min / 1.7 m 2;

50-60 years old 68-126 ml / min / 1.7 m 2;

60–70 years old 61–120 ml / min / 1.7 m 2;

after 70 years 55-113 ml / min / 1.7 m 2;

Women

1–30 years old 81–134 ml / min / 1.7 m 2;

30–40 years old 75–128 ml / min / 1.7 m 2;

40-50 years old 69-122 ml / min / 1.7 m 2;

50-60 years old 64-116 ml / min / 1.7 m 2;

60–70 years old 58–110 ml / min / 1.7 m 2;

after 70 years 52-105 ml / min / 1.7 m 2.

The level above the upper limit of the reference values ​​is observed: in the initial period of diabetes mellitus; with hypertension; with nephrotic syndrome.

Decrease in creatinine level:

Up to 30 ml / min / 1.7 m 2 - a moderate decrease in kidney function (it has no independent significance),

30-15 ml / min / 1.7 m 2 - renal failure (compensated, subcompensated),

A decrease in urinary creatinine excretion and an increase in blood creatinine is observed in patients with kidney damage. The daily excretion of creatinine in the urine depends on gender, age, and total muscle mass. This study is most important for assessing kidney function when it is part of the creatinine clearance test (Rehberg's test).

No special preparation for analysis is required.

Acute and chronic disorders of kidney function,

Diseases of the endocrine glands (thyroid, pituitary, adrenal glands),

Pregnancy,

Decreased muscle mass.

Creatinine norms: women after 14 years 5.3-15.9 mmol / day, men after 14 years 7.1-17.7 mmol / day.

An increase in creatinine levels can occur with: physical activity; acromegaly, gigantism; diabetes mellitus; infections; hypothyroidism; diet with a predominance of meat food.

A decrease in creatinine levels is possible with: hyperthyroidism; anemia; paralysis, muscular dystrophy, diseases with a decrease in muscle mass; advanced stage of kidney disease; leukemia; vegetarian food.

Creatinine decreases in the urine flowing from the kidney from the side of renal artery stenosis.

The urinary excretion of this calcium is closely related to bone metabolism, dietary calcium intake, and kidney function. When using a low-calcium diet, its content in the urine does not exceed 3.75 mmol / day.

Indications for the purpose of the analysis:

Assessment of the state of the parathyroid glands,

Diagnosing and checking the status of osteoporosis,

Diagnosis and control of treatment of rickets,

bone disease,

Diseases of the pituitary and thyroid glands.

Preparation for the study: diuretics should be excluded.

Calcium levels in urine:

Up to 6 weeks 0–1 mmol/day;

6 weeks - 8 months 0-1.62 mmol / day;

8–12 months 0–1.9 mmol/day;

12 months - 4 years 0-2.6 mmol / day;

4–5 years 0–3.5 mmol/day;

5–7 years 0–4.6 mmol/day;

7–10 years 0–7.0 mmol/day;

10–12 years 0–8.8 mmol/day;

12–14 years 0–10.5 mmol/day;

After 14 years 2.5-7.5 mmol / day.

An increase in the level of calcium excretion (hypercalciuria) can occur with: prolonged exposure to sunlight; hyperparathyroidism, Itsenko-Cushing syndrome, acromegaly; osteoporosis; an overdose of vitamin D (in many cases, hypercalciuria occurs before an increase in serum calcium levels); an increase in calcium in the diet and with a milk diet; thyrotoxicosis; some types of tumors; with prolonged immobilization; some specific diseases; taking medications (furosemide, ammonium chloride).

Sometimes the cause of hypercalciuria cannot be determined, and it does not entail negative consequences.

Decreased calcium levels (hypocalciuria) may be caused by: hypoparathyroidism, pseudohypoparathyroidism (parathyroid insufficiency); rickets; all cases of a decrease in the level of calcium in the blood (except those associated with kidney disease); many cases of nephrosis (non-inflammatory kidney disease); acute nephritis; bone tumors; hypothyroidism; some specific diseases.

This study is an indicator of the daily excretion in the urine of one of the important trace elements, magnesium. Magnesium deficiency can lead to disruption of the central nervous system, decreased muscle tone, and pathological pregnancy (miscarriages).

The main indications for the appointment: assessment of magnesium excretion, neurological pathology, renal failure, pathology of the cardiovascular system.

Determining the level of magnesium in the urine is of particular importance, as it allows diagnosing its deficiency even before changes in its concentration in the blood serum.

In preparation for the analysis, it is necessary to exclude diuretics from the diet.

Normal excretion of magnesium in the urine per day is 2.5–8.5 mmol/day (60–120 mg/day).

An increase in the content of magnesium in the urine can occur with: early stages of chronic kidney disease; insufficiency of the adrenal cortex (Addison's disease); alcoholism; regular intake of antacids containing magnesium; treatment with cisplatin.

A decrease in magnesium content can occur with: malabsorption syndrome; acute or chronic diarrhea; diabetic ketoacidosis; dehydration; pancreatitis; late stages of renal failure; insufficient magnesium content in food.

The amount of potassium excreted in the urine is highly dependent on age and diet. In newborns and children under 6 years of age, it is lower than in older children and adults. An increased excretion is called hypercaluria, a reduced one is called hypocaluria. The renal regulation of potassium excretion from the body depends on the acid-base balance. Potassium excretion is increased by many diuretics.

This analysis is prescribed for:

diet control; estimates of the balance of potassium intake and loss,

Control therapy of hormonal disorders, especially adrenal glands,

Estimates of the severity of intoxication,

Definitions of renal pathology,

In preparation for the analysis, it is necessary to exclude diuretics from the diet.

Children under 1 year 1-20 mmol / day,

1–4 years 10–30 mmol/day,

4–14 years 10–60 mmol/day,

Over 14 years 30-100 mmol / day.

An increase in the level of potassium in the urine (hypercaliuria) can be due to: the intake of potassium from the cells (trauma, sepsis, transfusion of red blood cells with a shelf life of more than 7 days); the beginning of fasting; Cushing's syndrome, primary and secondary aldosteronism; primary kidney damage; treatment with ACTH, hydrocortisone, cortisone, mercury diuretics and diacarb.

A decrease in the level (hypocaliuria) can be observed in: a state of chronic potassium deficiency in food; loss of potassium (vomiting, diarrhea); Addison's disease; renal diseases with a decrease in urine outflow (severe glomerulonephritis, pyelonephritis, nephrosclerosis).

The excretion of sodium in the urine changes with age and is very dependent on its intake with food and the state of the body's water balance. In newborns, this indicator (sodium clearance) is only 20% of that in adults. Changes in the sodium content in the urine reflect violations of its intake into the body, metabolism and excretion. The most important cause is hypovolemia (decrease in circulating blood volume).

Indications for the purpose of the analysis:

kidney pathology,

Controlling the use of diuretics

diet control,

diseases of the adrenal glands,

Traumatic brain injury.

In preparation for the analysis, it is necessary to exclude diuretics from the diet.

Children under 1 year 1-10 mmol / day,

Children 1-7 years old 10-60 mmol / day,

Children 7-14 children 40-170 mmol / day,

People over 14 years old 130-260 mmol / day.

An increase in sodium levels is observed with: increased sodium intake; postmenstrual diuresis (physiological state); adrenal insufficiency (primary or secondary); jade with loss of salts; treatment with diuretics; diabetes mellitus; some specific diseases; any form of alkalosis or other condition in which the urine becomes alkaline.

A decrease in sodium levels is observed with: reduced sodium intake; premenstrual sodium and water retention (physiological state); extrarenal sodium loss with normal water intake; the first 24-48 hours after surgery (diurtic stress syndrome); diarrhea excessive sweating; some specific diseases.

Inorganic phosphorus is one of the main mineral components of bone tissue (it contains more than 80% of the total amount of phosphorus in the body). It is part of many biologically important substances, participates in many metabolic processes and is necessary for the normal functioning of all body cells, including cells of the central nervous system. Urinary phosphorus excretion varies greatly and depends on the diet. Its content in the urine with a constant diet is less than 32.3 mmol / day, with a diet without restrictions - up to 42.0 mmol / day. There are significant diurnal fluctuations in the excretion of phosphorus in the urine with maximum values ​​in the afternoon. With a standard diet, changes in the excretion of phosphorus may be the result of pathological processes in the skeletal system and kidneys. Indications for the purpose of the analysis:

Diseases of the skeletal system

Diseases of the parathyroid glands,

prolonged immobility,

Vitamin D treatment

Kidney diseases.

In preparation for the analysis, it is necessary to exclude diuretics from the diet.

Phosphorus rates:

Children under 1 year 0.6-15 mmol / day,

1–4 years 1–25 mmol/day,

4–7 years 10–30 mmol/day,

7–14 years 15–40 mmol/day,

Over 14 years 12.9-40 mmol / day.

An increase in the level of phosphorus (hyperphosphaturia) can occur with: rickets; prolonged immobility; damage to the renal tubules; familial hypophosphatemia; predisposition to the formation of urinary stones; leukemia.

Decreased phosphorus levels (hypophosphaturia): tuberculosis; enterocolitis; infectious diseases; hypofunction of the thyroid gland; some specific diseases; starvation.

Indications for the purpose of the analysis:

Diagnosis of disorders of purine metabolism (gout),

Diagnosis of endocrine diseases,

blood diseases,

lead poisoning,

Suspicion of dietary folic acid deficiency.

Uric acid levels:

Children under 1 year old 0.35-2.0 mmol / day;

Children 1–4 years old 0.5–2.5 mmol/day;

Children 4–8 years old 0.6–3.0 mmol/day;

Children 8–14 years old 1.2–6.0 mmol/day;

People over 14 years old 1.48-4.43 mmol / day.

An increase in uric acid levels can occur with: gout; leukemia; viral hepatitis; sickle cell anemia; lobar pneumonia; epilepsy; some specific diseases.

A decrease in uric acid levels can occur with: folic acid deficiency; lead poisoning; increasing muscle atrophy; taking medications: potassium iodide, quinine, atropine.

This is the most important indicator of the efficiency of excretion of the end product of protein metabolism. The study of urea in the blood and urine allows you to assess the state of protein metabolism, differentiate kidney disease from liver disease. Normally, about 20 g of urea nitrogen is excreted in the urine per day. Determination of clearance by urea nitrogen is used to assess kidney function. Normally, this indicator is in the range of 40-60 ml / min. A high concentration of urea nitrogen in the blood and a low concentration in the urine (below 10 g / l) indicate renal failure.

Indications for the purpose of the analysis:

Diseases of the kidneys and liver,

Pregnancy,

diet control,

Tracking the healing process.

Children under 1 year 10-100 mmol / day;

Children 1–4 years 50–200 mmol/day;

Children 4–8 years old 130–280 mmol/day;

Children 8-14 years old 200-450 mmol / day;

People over 14 years old 428-714 mmol / day.

An increase in the level of urea can occur with: a diet with a high protein content; hyperthyroidism (low function of the thyroid gland); postoperative period; excessive administration of thyroxine; increased muscle load; fever diabetes.

A decrease in the level of urea can occur during: pregnancy; diet low in protein and high in carbohydrates; liver diseases; kidney disease and kidney failure; the use of testosterone, insulin, somatotropin; fasting; transfusion of incompatible blood.

The level of urea also rises during the recovery period.

Specific gravity(second name - relative density) of urine - an indicator that characterizes the work of the kidneys and makes it possible to assess how well they cope with the function of filtering and removing unnecessary compounds from the body.

By studying the density of the biological fluid, the laboratory assistant determines what is the content in it:

• Creatinine.
• Urea.
• uric acid.
• sodium and potassium salts.

It is by the values ​​of these parameters that the above criterion is calculated.

Specific gravity of urine: normal indicators for men, women and children

Determination of the density of urine is carried out in a laboratory using a special device - urometer. In order for the data obtained to be true, the patient must correctly collect material for the study (do not drink alcohol the day before, a lot of liquid).

Slight fluctuations in the parameter during the day is a normal physiological reaction. This is due to changes that occur during eating, drinking water, doing heavy physical work, resting, sweating, etc. Under different conditions, the kidneys of a healthy person excrete urine, the density of which is normally equal to from 1.010 to 1.028.

In men and women who do not have diseases of the urinary system, with moderate physical exertion, the specific gravity of morning urine is most often from 1.015 to 1.020. As for children, their figure may be slightly lower.

For children, the norm option is from 1.003 to 1.025. In the first week of life, the specific gravity of the urine of the child should be within up to 1.018, starting from the second week and until the end of the second year - from 1.002 to 1.004.

Later, the indicator begins to rise and, during normal kidney function, is already from 1.010 to 1.017. In children 4-5 years of age, the density is 1,012-1,020 . For children over 10 years old, it should be in the range from 1.011 to 1.025.

Causes of a decrease in the specific gravity of urine

If the density of the biological fluid is below normal, they talk about hypostenuria. This does not necessarily mean that the person is sick. Physicians are aware of cases where such a deviation was the result of the patient drinking an excessive amount of liquid shortly before the laboratory test.

Also, the use of any diuretic drugs leads to hypostenuria. The doctor must be warned about this factor in advance so that the data obtained are not misinterpreted.

What diseases cause a decrease in the specific gravity of urine

If we talk about the pathological causes of hypostenuria, they are as follows:

• Diabetes.
• Polydipsia (usually seen in people with unstable mentality)
• Neurogenic and nephrogenic diabetes insipidus.
• Inflammation of the renal tubules.
• The presence in the body of unresolved infiltrates.
• Untreated or complicated pyelonephritis.
• Chronic renal failure.
• Compliance with an overly strict diet, lack of vitamins, trace elements and minerals in the diet.
• The presence of nodular formations on the renal tissues.
• Hormonal failure (typical for women of childbearing age, as well as during menopause).

Many patients with a significant decrease in the described indicator complain of:

• The appearance of edema on different parts of the body, limbs.
• Pain in the lower abdomen or lower back.
• Decrease / increase in the volume of urine separated.

All these symptoms indicate problems with the kidneys, so when they appear, you should contact a qualified doctor as soon as possible and undergo an examination.

What to do with a low specific gravity of urine

If the specific gravity of urine is much lower than normal, first of all, it is necessary retake laboratory tests. Be sure to take a responsible attitude to the re-collection of biological fluid, on the eve of the diagnosis, do not drink too much liquid. If other indicators are normal, then most likely the person does not have any kidney disease.

If, in addition to low density, there are other deviations in laboratory tests, a comprehensive examination is mandatory. What it will include, the therapist or urologist must decide. Usually, patients are given referrals for an analysis according to Zimnitsky, which allows you to establish differences in urine density at different times of the day.

Specific gravity of urine during pregnancy

It is considered normal if the relative density of urine in the expectant mother is from 1.010 to 1.029.

The parameter reduction is provided by:

• Excessive fluid intake.
• Edema.
• Hormonal surges.
• Kidney pathologies (nephropathy)
• Toxicosis.
• Frequent urination.

If the criterion, on the contrary, is increased in a pregnant woman, the gynecologist may assume the presence of:

• Diabetes.
• Fluid deficiency, dehydration.
• Inflammation of the kidneys.
• Severe toxicosis / gestosis.

The expectant mother should not worry if the results of the analysis were unsatisfactory. The analysis should be retaken as soon as possible. Only if the re-diagnosis confirms the concerns that have arisen, the measures necessary to determine the cause of the condition will be carried out.

The specific gravity of urine is increased - causes and what to do

An increase in the specific gravity of urine in medicine is called hyperstenuria. Usually this problem develops against the background of a decrease in the amount of separated biological fluid.

It can be provoked by:

• Severe vomiting, nausea.
• Inadequate fluid intake, dehydration.
• The introduction of a radiopaque substance into the patient's body on the eve of a laboratory study.
• Proteinuria (presence of protein) in nephrotic syndrome.
• Diabetes.
• Taking large doses of antibiotics.
• Inflammation of the organs of the genitourinary system.
• Toxicosis during pregnancy.

Hyperstenuria is characterized by symptoms such as:

• Discomfort in the abdomen.
• Pain in the lower back.
• The formation of edema for unknown reasons.
• A sharp decrease in single portions of excreted urine.
• Weakness, fatigue.

With hyperstenuria, as with hypostenuria, the patient should undergo a Zimnitsky test to understand if there are abnormalities in the work of the kidneys and get a complete picture of their functioning.

The specific gravity of urine is one of the key parameters of the general analysis. WHO has established standards for the results of studies of the specific weight in various categories of citizens: children, men, pregnant women, etc.

The relative density of urine can change quite quickly under the influence of the following factors:

• Diet;
• Drinking mode;
• The intensity of physical activity;
• Sweating intensity.

Any process of excretion and accumulation of fluid in the body able to influence on the specific gravity of urine.

How is it defined?

Laboratory research is carried out using a special device - urometer (hydrometer). Measuring scales allow you to determine the specific gravity of urine in the range from 1,000 to 1,060 g/l.

50-100 ml of urine is carefully collected in a cylinder, trying to avoid foaming. If the foam still comes out, it is removed with filter paper. The device is immersed in urine in such a way that its upper part remains above the liquid level.

When the urometer stops diving on its own, it needs to be pushed slightly with your fingers, as it does not sink completely. The movement of the hand creates slight vibrations. It is appropriate to determine the relative density of urine only after the complete cessation of fluctuations.

The urometer should not come into contact with the walls of the container, so choose a cylinder with a diameter larger than the widest part of the device.

When a small amount of urine (20-50 ml) is provided for analysis, diluted with distilled water to the required volumes and carry out the measurement in the prescribed manner. The last two digits of the set indicator are multiplied by the degree of dilution.

It is possible to determine the parameters of the specific gravity of urine, even if only a few drops were collected for analysis. In this case, the method of a mixture of liquids is used.

A mixture of benzene with chloroform is poured into a cylindrical container and the collected urine is injected with a pipette. If drops of urine sink, then its relative density is higher than the parameters of the mixture; if the drops fall on top, then the density is lower.

By adding small amounts of chloroform or benzene to the mixture, the mixture is adjusted until the drop of the test urine is exactly in the middle of the tank. "Averaging" of the drop means that the specific gravity of the urine has become equal to the specific gravity of the solution, which is easy to determine in the laboratory.

When starting laboratory tests, it is necessary to observe its rules:

1. Ambient temperature = 15 degrees Celsius (3 degrees tolerance allowed);

Some urometers are calibrated to measure at 20 or 22 degrees. Pay attention to the instructions on the instrument case.

2. Absence of protein or glucose in the material;
3. , smell, transparency and acidity of urine.

Functional trials

When deviations from the norm are detected by OAM, as a rule, additional functional tests are prescribed. and a concentration test allow you to assess the general condition of the kidneys, their ability to concentrate and excrete with salts.

According to Zimnitsky

Laboratory study evaluates the functional ability of the kidneys in a patient without drinking diet. A person collects 8 portions of urine, urinating every 3 hours within one day.

The urometer examines the relative density of each portion of urine and the resulting volume. The result of the study shows an objective difference between day and night, while nighttime diuresis should be about 1/3 of the daytime one.

How to properly collect a urine test according to Zimnitsky, read our article.

concentration

Preparing the patient for the analysis is in the daily exception from his diet of drinking liquids in any form. Urine is collected every 4 hours. Each portion is examined using a urometer and the results are analyzed.

If the specific gravity fits into the range of 1.015-1.017 g / l, this means that the patient's kidneys do not cope with the main function and do not concentrate urine in the required volume. Such a state is called isostenuria.

What are the normal intervals for the specific gravity of urine?

During the day, the relative density of urine fluctuates and deviates from the norm within 0.001-0.005 g/l. Averages for people of various categories:

• Newborn up to 5 days - 1.008-1.018;
• From 5 days to 2 years - 1.002-1.004;
• Child 2-3 years old - 1010-1.017;
• Child 4-5 years old - 1.012-1.020;
• Child 6-17 years old - 1.011-1030;
• Adult - 1,010-1,025;
• Pregnant woman - 1.003-1.035.

Most informative there will be an analysis of night or first morning urine, since in a dream a person’s breathing slows down, the intensity of sweating is reduced and the liquid does not come from outside.

Deviation from the norm: causes and consequences

High and low density urine in medical terminology is referred to as hyperstenuria and hypostenuria, respectively.

Both conditions indicate a violation of the normal water-salt metabolism in the body and often make it possible to identify functional diseases and pathologies in the human body.

Hyperstenuria

Increased specific gravity of urine usually accompanied by quite obvious swelling. This symptom may indicate the development of glomerulonephritis or.

In addition, hyperstenuria is characteristic of various endocrinological diseases, when hormonal dysfunction reduces fluid levels in the human body.

Causes of hyperstenuria:

• Physiological processes associated with a significant loss of fluid (profuse vomiting and diarrhea, increased sweating, bleeding, burns of a large area, etc.).
• Injuries to the abdomen, back, intestinal obstruction.
• Toxicosis in women during pregnancy.
• Chronic diseases of the urinary system.
• Taking high dose antibiotics.
• Endocrine diseases with a violation of the natural metabolism.

Physiological hyperstenuria does not require medical intervention. The specific gravity of the urine will return to normal levels as soon as the body replaces the fluid loss.

Symptoms of hyperstenuria:

• Decrease in the volume of urine excreted.
• urine.
• Increased urine odor.
• Puffiness.
• Weakness, drowsiness and fatigue.
• Girdle pain in the abdomen and back.

As noted above, the increase in urine weight may be due to the presence of glucose or protein in the urine. If one of these components is detected in the urine, additional functional studies are prescribed.

Hypostenuria

The concentration of dry residue in the urine is below normal, decrease in its relative density occurs due to an increase in fluid intake or the development of pathological processes within the body.

Causes of hypostenuria:

• - acute inflammatory process in the kidneys.
• Chronic diseases of the urinary system.
• Non-diabetic mellitus of a different nature (neurogenic, nephrogenic, during pregnancy, etc.).
• Increase fluid intake.

Symptoms of hypostenuria:

• An increase in the volume of urine excreted.
• Light color urine.
• Paleness of the skin.

Often hypostenuria is asymptomatic and to identify deviations from the norm is possible only by conducting a general analysis of urine.

How to normalize the specific gravity of urine?

When deviations from the norm of the specific gravity of urine are caused by physiological reasons, then normalization occurs without medical intervention. As soon as the body replenishes the loss of fluid or removes the excess, the relative density indicator will return to normal.

If hyperstenuria or hypostenuria are manifested against the background of diseases, then it is possible to normalize the specific gravity of urine only through therapeutic intervention or elimination of the pathological cause.

What is encrypted in the clinical urinalysis forms, see the video:

To date, any diagnosis involves a number of laboratory tests. The general analysis of urine and blood is carried out most often. An informative indicator in OAM is the relative density of urine (SG), which allows you to identify impaired renal function (hyper-, hypostenuria, isosthenuria).

Normal Relative Density

The concentration ability of each kidney is determined by the specific gravity of urine, the norm of which is determined in the general analysis. Urine excreted from our body is considered secondary. At the first stage of filtration, the blood, passing through the glomerular structures, separates large components. This is primary urine, which differs from blood in the absence of proteins and blood cells. In the final sections of the filtration apparatus, a larger amount of water is absorbed along with the ions necessary for the body. As a result, only 2 liters of secondary urine are filtered per day, while the primary is about 70 liters.

The less water a person drinks during the day, the more concentrated his urine becomes. An increase in the density of urine is reflected in the interpretation of the analysis as hyperstenuria. Conversely, with an excess amount of water drunk, a decrease in urine density is observed, referred to as hypostenuria. At the same time, the average daily volume of excreted biological fluid also changes.

The norm of the specific gravity of urine in adults according to the urometer should not go beyond the range of 1.015-1.025. The body of a child differs from an adult in incomplete processes of formation and adaptation. Therefore, the specific gravity of urine in children is different and depends on their age. An infant up to a year has a rather low density of urine, it is 1.010. The older the child, the higher the level of density can be determined. This depends on the ability of the distal tubules to reabsorb water and chemicals.

The study of the concentration of dry urine residue

The process of determining the specific gravity of urine is simple, but it requires special equipment. The relative density of urine is determined by a special device - a urometer at a temperature of 15 ° C and in the analysis has the designation SG. In clinical laboratories, as a rule, universal urometers are used. By analyzing urine, specific gravity can be determined within a division scale from 1.000 to 1.050. The specific gravity of urine corresponds to the position of the lower meniscus on the scale of the urometer. The physiological reasons for changes in the density of urine are different:

• temperature fluctuations in the external environment;
• evaporation of water during the act of breathing;
• food irritants (spicy, salty, fatty and fried foods);
• water imbalance.

Vegetative dominance at night slows down breathing and sweating. There is no water factor at night, which is why it is most informative to take OAM in the morning.

The concentration of urine in women is more prone to various changes and requires more attention. Evaluation of the filtration and concentration functions of the kidneys involves a whole range of tests. Physiological change in the level of specific gravity of urine is cyclical to the daily rhythm. Therefore, for a complete picture, it is necessary to carry out monitoring throughout the day.

The Zimnitsky test can be carried out in a child, as well as in men and women. Such a study is most often carried out in hospitals, since the analysis is collected at 8 time intervals in different containers. The amount of fluid consumed should not be artificially increased, otherwise the result will not be accurate. The volume of each sample is determined, the specific gravity of the test material in each portion (collected in 3 hours) is determined by the urometer. Normal diuresis per night should not exceed 20 - 35% of the daytime. If the amount of nocturnal diuresis increases, a condition called nocturia occurs. It indicates renal or postrenal disorders.

Increased urine density is recorded at a specific gravity of more than 1030 and indicates excessive water reabsorption. Hypostenuria characterizes a decrease in the specific gravity of urine to 1002-1012. Hypoisostenuria is diagnosed when the density drops below the norm (1010) for a whole day with a fluctuation of no more than 10. The kidneys lose their concentration ability.

The concentration test is carried out with the complete exclusion of liquid, the intake of protein products is allowed. Urine is collected every 4 hours in different containers. The interpretation of the results is similar to the Zimnitsky test. It is important that all the rules for collecting and examining urine are followed, and that the urometer is in good working order.

Increased specific gravity of urine

The specific gravity of urine is increased in diseases of various systems of the human body. Hyperstenuria is characterized by severe swelling of various parts of the body. Density above the norm is determined under the following conditions:

• fluid loss not with urine (sweat, vomiting, diarrhea, bleeding, massive burns);
• large doses of nephrotoxic antibiotics;
• injuries of the digestive tract;
• small or large intestine obstruction;
• diseases of the excretory system;
• endocrine disorders with metabolic disorders.

Most often, the concentration of dry residue exceeds normal values ​​in renal failure, glomerulonephritis or pyelonephritis. Also, the density of urine is increased with endocrine pathologies. The hormones vasopressin and aldosterone have a major effect on fluid retention in the body. Thus, due to the increase in the concentration of dry residue, a high urine density is formed.

When the relative density of urine shows an excess of permissible values, a non-specific clinical picture can be noted:

• decrease in the amount of excreted urine to oliguria;
• darkening of its shade;
• unpleasant specific aroma;
• swelling;
• pronounced astheno-vegetative syndrome;
• pain in the abdomen or lumbar region.

The density of urine in children, the norm of which is always less than in adults, can sometimes increase. The highest fluid loss for a baby during intestinal infections makes urine more concentrated, creating a lot of adverse effects. All unnecessary metabolic products do not have time to be removed from the child's body, leading to intoxication of the fragile organism. This is especially pronounced in infants, since the work of most of their systems is not yet perfect.

Often infectious and gastrointestinal diseases require plentiful drinking. Water supplies are replenished with a surplus. Gradually, the amount of dry residue in OAM becomes small. The low specific gravity of urine is normalized only after the full recovery of the body. This condition is considered physiological and does not require drug correction.

Reduced specific gravity can be detected with polydipsia. This is a state characterized by constant thirst. To satisfy it, patients drink an amount of water that is several times higher than the norm. As a result, the excreted metabolic product is not concentrated and in large quantities. Unfortunately, this disease often manifests itself in mentally unstable people.

Neurogenic diabetes insipidus is characterized by thirst and frequent urination. Such diabetes often develops with craniocerebral injuries, infectious lesions, tumor processes, intracranial surgical interventions. The hypothalamus synthesizes an insufficient amount of the hormone vasopressin, and it cannot fully perform its functions. The fluid is irrevocably excreted, and even compensation with water intake does not save, since vasopressin is still not enough to maintain water reabsorption at the desired level.

In situations where the hormone is produced in sufficient quantities, and urine is still excessively excreted, there may be a loss of receptors sensitive to vasopressin by the kidney. Nephrotoxic drugs, polycystic disease, chronic renal failure, urolithiasis, and congenital renal anomalies are only a small part of the causes of neurogenic diabetes insipidus. The absence of predisposing factors for diabetes forces the diagnosis of an idiopathic disease.

Density in the analysis of urine below the norm is also observed in chronic glomerulonephritis, amyloidosis of the kidney, acute pyelonephritis. But the most common pathologies with reduced urine density are in diabetes mellitus (nephrogenic and neurogenic etiology).

In the differential diagnosis of diabetes mellitus, the determination of glucose and protein, which are often elevated, will be very useful.

Changes in the relative density of urine in pregnant women

During pregnancy, the indicator of the concentration ability of the kidneys can both increase and decrease. Since dehydration in expectant mothers mainly occurs with toxicosis, it is this condition that more often than others increases the specific gravity of urine.

If the specific gravity of urine is lowered for pathological reasons, then this should be taken seriously. Such diseases include diabetes insipidus in pregnant women and in patients with nervous disorders. Urine analysis during pregnancy may differ in a small specific gravity, what does this mean? There may be several reasons. Firstly, this is a decrease in renal functionality due to a pressing uterus and an increase in load. Secondly, hormonal changes significantly affect all levels of regulation, which also affects the urinary system. These factors tend to reduce the density by increasing the excretion of fluid in pregnant women from the body.
Many of the conditions discussed are very serious and require special attention. It is necessary to monitor the condition of your kidneys in order to prevent adverse and even dangerous complications.

The specific gravity of urine in the norm indicates a good condition, primarily of the kidneys. Deviation of the concentration ability from the norm, especially persistent, requires a number of additional examinations, consultation with a competent nephrologist and the appointment of the necessary treatment. It is worth taking care of your health and taking tests more often, because timely identified violations are always easier to eliminate.