Relative density of urine. What does low relative gravity of urine mean?

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.

General clinical tests help diagnose many diseases. The specific gravity of urine is a standard for general urine analysis, which indicates the ability of the kidneys to collect, purify and excrete primary urine. Deviations in this indicator allow us to talk about many diseases, increase the likelihood of their early detection, which means that treatment can be started on time.

Laboratory study of urine for specific gravity allows you to see a number of pathologies of internal organs.

How is urine formed?

The appearance of urine in the kidneys takes place in three stages: filtration, secretion. The first of these occurs in the renal glomeruli. Here, salts, toxins, glucose, creatinine and other chemical substances are filtered out of the blood. This results in 180 liters of primary urine. The second stage occurs in the tubules of the kidneys and is characterized by the return of the nutrients needed by the body to the bloodstream. At the last stage, hydrogen, potassium, ammonia and drugs enter the urine. After that, 1.5-2 liters of secondary urine is formed, which enters the bladder and is excreted.

Reasons for urine specific gravity analysis

Urine examination demonstrates the ability of the kidneys to collect, purify and excrete it. This indicator is called specific gravity, which is determined by the abundance of substances soluble in it and depends on the amount and nature of the food and liquid taken. A low specific gravity of urine will be observed if the body receives little water, and, conversely, with increased hydration.

Urine analysis

When analyzing urine for specific gravity, values ​​​​are compared by 7 parameters.

A general urine test makes it possible to determine the physical and chemical properties, as well as the results. Normal urine has a light straw color. It is transparent, with a slight odor and a specific gravity of 1012-1025. The ratio of daytime and nighttime diuresis is 3:1. The chemical properties of urine, as well as the number of sediment elements, will differ depending on the age and sex of the patient. Most of the normal analysis indicators are shown in the table.

Urine density norm

Urine contains uric acid, its salts, creatinine and other elements. Their abundance determines the density of urine. The determination of specific gravity is carried out in the laboratory with a urometer or at home using a test strip. Normally, in an adult, it should be in the range of 1012-1025. In a child up to a year old, the concentration is lowered to 1002, but as it grows, the indicator increases and reaches adult norms by the twelfth year. The determination of the specific gravity of urine is carried out in a portion collected in the morning on an empty stomach. The relative density of urine is a variable value. Its increase or decrease is due to:

• food intake;
• temperature conditions of the environment;
• loss of fluid through perspiration and breathing.

Increased urine density

An overestimated specific gravity of urine occurs with glomerulonephritis, heart failure, diabetes mellitus, diathesis.

The deviation of this sign above the norm is hyperstenuria. Such an increase may be due to a lack of water in the body or a reaction to the appearance of edema. It is observed with oliguria in patients with acute glomerulonephritis, heart failure, edema, as well as during pregnancy with toxicosis, diabetes mellitus, hypovolemic conditions,. An increased specific gravity of urine can be after intravenous infusions, taking certain medications, thermal damage, and prolonged dyspeptic manifestations. With hyperstenuria, a rather small daily diuresis, the color of the urine becomes saturated, a pungent odor appears. There are swelling in various parts of the body, pain in the abdomen and lower back, high fatigue.

Decreased density of urine

If the specific gravity of urine is lowered, then they speak of hypostenuria. The condition can develop under the influence of extrarenal causes, for example, due to a lack of secretion of antidiuretic hormone or renal - associated with abnormalities in the functioning of the glomerular and tubular nephron and a decrease in their cumulative capacity. In this case, the patient notes symptoms such as thirst, increasing swelling in the head and limbs, lumbar pain, and itchy skin. A decrease in the specific gravity of urine below the norm is manifested if diagnosed:

• diabetes insipidus;
• chronic kidney failure;
• parenchymal kidney disease - pyelonephritis, glomerulonephritis;
• kidney cyst;
• polydipsia.

The density of urine is an indicator that changes physiologically and pathologically. It is possible to establish the cause and range of the deviation using a general analysis and subsequent consultation with a specialist.

What is a stably reduced density level?

Reduced urine density in all daily portions is characteristic of pyelonephritis in remission, insufficient kidney function, and diuretic therapy. Hyperisosthenuria is a state when the level of density is equally increased, observed in diabetes mellitus, hypovolemic conditions, and uric acid diathesis. Hypoisostenuria - means the presence of severe pyelonephritis and tubulopathies.

Laboratory examination of urine, an integral part of modern diagnostics. One of the varieties of such analyzes is the analysis of urine for its specific gravity. The deviation of this parameter from the norm can indicate the causes of a particular disease, which is extremely important in the diagnosis.

What is the specific gravity of urine?

The relative specific gravity of urine shows the saturation of suspended in it:

• Urea;
• uric acid;
• Creatinine;
• Potassium, sodium in the form of their salts.

The relative specific gravity of urine is directly related to the amount of urine excreted at a time and to the frequency of bladder emptying. Urine excreted frequently and in large portions has a low density and vice versa, small portions show a high concentration. The relative specific concentration of urine is a reliable indicator of the health of the kidneys, or rather, their ability to concentrate. For example, the reasons for a decrease in the relative density of urine may lie in diseases that cause kidney failure, accompanied by a decrease in their filtering and absorption properties. This condition is called hypostenuria. If the concentration of urine is increased, they speak of hyperstenuria.

Normal urine density

Norms depend on the gender and age category of the patient. For newborns, the normal density is 1008 - 1018 grams per liter of liquid, in children of two, three years old 1007 - 1017, children of four, twelve years old are considered healthy at 1012 - 1020 grams per liter.

For people of mature age and adolescents aged 13 years and over, indicators of the normal specific gravity of urine fluctuate between 1010 and 1020 g / liter.

Deviations from these norms give rise to at least a consultative examination by an endocrinologist and a nephrologist to determine the cause.

Specific gravity above normal

Hyperstenuria - this is the name of this phenomenon, expressed by a significant excess of the permissible density of urine. It is diagnosed at a high specific gravity - above 1030 grams per liter of liquid. The reasons that cause it can be:

• Diabetes;
• Glomerulonephritis with nephrotic syndrome;
• Dehydration due to diarrhea, vomiting, severe body heat or insufficient fluid intake;
• Large doses of antibiotics and other medications;
• Toxicosis, including toxicosis during pregnancy;
• Inflammation of the urinary system.

Symptoms of hyperstenuria:

• A sharp decrease in single portions of excreted urine;
• Changing the shade of urine towards dark tones, often interspersed with clots;
• The occurrence of pain in the abdomen;
• Chronic weakness and lethargy;
• General swelling without visible localization.

Specific gravity is too low

The state of a noticeable decrease in the relative specific gravity of urine, in comparison with the norm, is called hypostenuria. With it, the specific gravity of urine is significantly less than the lower limit of the norm. The cause of this deviation may be excessive consumption of water, juices and any other liquids. Men, for example, often abuse beer, which may well affect the indicator of the relative specific concentration of urine in the direction of its strong decrease. If we talk about pathological processes that contribute to hypostenuria, then the following can be distinguished:

• Diabetes (diabetes);
• Regeneration of edematous infiltrates at the end of inflammatory processes;
• A low-calorie diet with a lack of enzymes and vitamins, leading to a dystrophic condition;
• Protracted pyelonephritis;
• Chronic forms of renal failure;
• Nephrosclerosis is a disease that provokes a change in the structural tissue of the kidneys (the formation of nodes);
• Glomerulonephritis;
• Interstitial nephritis;
• Taking diuretics in violation of the doctor's recommendations;
• Excessive drinking.

Both hyperstenuria and hypostenuria can cause serious negative consequences, so it is desirable to identify it in the early stages. These conditions are relatively easy to diagnose, using the general method of urine testing and the Zimnitsky scheme, therefore, people with a predisposition to such problems should be examined regularly.

What to do if the specific gravity of urine deviates from the norm?

It is desirable to treat such conditions in a hospital or at least under the constant supervision of a doctor - an endocrinologist, nephrologist or pediatrician. Patients with diabetes, at the slightest hint of a change in the density of urine, should take the advice of a doctor especially responsibly, since diabetes can provoke a rapid development of events and seriously complicate the cure. In this case, it is very important to diagnose the cause of the pathology at an early stage of development and immediately begin to eliminate it.

Fundamentally, the treatment of this disease does not differ from any other, since a thorough diagnosis reveals the cause, that is, a diseased organ that creates problems for the entire body, and allows you to subsequently prescribe a set of treatment tactics. Prescribed drugs should act, first of all, directly on the source of the problem and affect healthy organs as little as possible.

If the problem is in kidney failure, a mandatory factor in a successful cure is a sparing diet and a healthy lifestyle. The diet should be devoid of spicy, smoked, salted foods and contain as little as possible culinary spices. Giving up smoking and alcohol is not even discussed. Drug treatment, in case of its inevitability, should be carried out strictly according to the recommendations of the attending physician and under his constant supervision.

If the phenomenon of hypostenuria or hyperstenuria is observed in a patient in a chronic cycle, then such patients are registered with a doctor and require a systemic examination every three months with a mandatory urinalysis and, possibly, blood.

Quite often, hyperstenuria in diabetes mellitus is a side symptom of it. A feature of this pathology is an increased level of sugar in the blood, which leads to increased urination, and this, in turn, requires the consumption of more fluid to restore water balance. Ultimately, this can lead to disruption of the kidneys and the entire urinary system.

If the patient has diabetes mellitus, then the treatment is monitoring the state of blood sugar, regular examination by a nephrologist in compliance with all his recommendations. Unfortunately, the disease is chronic and incurable, so you can only control its course in order to avoid side effects in the form of disruption of the renal system.

Urine has a specific set of indicators, consisting of color, smell, acidity and specific gravity. The relative density of urine is determined from the amount of dissolved and undissolved substances, the norm of which is individual for each patient and depends on a number of indicators.

The work is carried out using the sense organs and medical equipment, which allows you to perform a number of manipulations and actions that help to study all the properties of urine. This procedure can only be carried out in the laboratory, subject to a number of measures and restrictions, without which it is impossible to obtain a reliable result.

Valid values

During the day, a person performs any actions, eats, sleeps, and as a result of these actions, the kidneys work differently.

From certain conditions, lifestyle and time of day, a relative density of 1.001-1.040 stands out. In the urine of an adult who does not suffer from chronic diseases, these figures range from 1.015-1.020; in children, the norm of urine density is 1.003-1.025.

These indicators, which are considered the norm, have a fairly large range. How well the kidneys function depends on the density of urine. With abundant drinking, morning urine is quite saturated, because at night the liquid does not enter the body.

You also need to pay attention to color and smell. A straw-yellow hue and the absence of a pungent odor indicate an acceptable indicator.

The following parameters should be considered for people of different ages:

• newborns up to 10 days of life from 1.008-1.018 g / l;
• children from two to four years old from 1.01-1.017 g / l;
• up to 12 years from 1.012-1.02 g / l;
• after 12 years and adults from 1.010-1.022 g / l.

The relative density of urine in an adult and in a child is influenced by many components. For example, in children of 6 months, 1.002-1.004 is considered the norm, from 6 to 12 months - the acceptable range is from 1.006-1.010.

Regardless of the age of the child, urine must be collected in an amount of at least 50 ml so that specialists in the laboratory can work and conduct research with a sufficient amount of material.

Deviations from the norm

Any disease detected at an early stage of the course is much easier to treat than a rapidly progressing pathology. This pattern is especially relevant for young children, who get sick more often and more severely than adults. The appearance of the first alarming symptoms should not be ignored - this will avoid serious complications. Laboratory studies of the specific gravity of urine in children help to detect a disease that is just beginning to emerge in the baby's body. Not always a decrease or increase in the indicator indicates the presence of a pathology - for a certain age this is the norm that does not require treatment.

What does the specific gravity of urine in a child show?

Experienced parents have long learned to decipher the mysterious numbers and terms printed on the form with the results of the tests. No wonder, because every visit to the hospital ends with the delivery of blood and urine by the child. But most dads and moms pay attention to the content of leukocytes and protein breakdown products, and not to the specific gravity of urine. But in vain - the relative density of urine signals the beginning of negative processes in various systems of life.

This parameter assesses the ability of the kidney to concentrate and dilute urine for optimal excretion of all harmful substances. In order for toxic compounds to quickly leave the baby's body, the kidneys filter the blood, regardless of the volume of fluid circulating in the body. If there is little water in the blood, then concentrated secondary urine is formed. It contains a lot:

• urea and its compounds;
• chlorides and sulfates;
• creatine.

When pathologies occur, dissolved ammonia and pathogenic microorganisms appear in the urine, which do not occur in normal health.

You can visually determine that the child's urine is thickened: it becomes darker in color, and its separated volume is relatively small.

With a large volume of fluid in children, highly dilute urine with a small amount of dissolved solids is formed. The kidneys experience a double load: they filter out harmful substances and remove a lot of fluid. Such urine is completely transparent in appearance, odorless and colorless.

The relative density of urine allows you to detect pathologies in the early stages

How is the determination of the relative density of urine

When the test results of children strongly deviate from the norm, parents have reason to worry. First of all, you should make sure that there is no error due to incorrect collection of urine. Only morning urine, which is placed in a clean, dry container, is suitable for analysis. You can purchase a special sterile container at the pharmacy - it does not need to be washed and dried. Baby urinals are great for newborns:

• for boys;
• for girls;
• universal.

The child must be washed with warm water using hypoallergenic soap. Now the most difficult thing remains - to catch the moment of urination. Almost all parents know the special signs that precede this moment: babies tense up, frown or wince. An average portion of urine is best for determining specific gravity.

It is not necessary to collect urine even in a dry and clean pot, the required sterility is violated, and this will lead to erroneous test results. Sometimes moms and dads just squeeze a diaper or diaper into the container. Such urine can not be taken to the laboratory - the parameters obtained will have a lot of errors.

The relative density of urine is determined using a special urometer device. The child's urine is placed in a cylinder, and the resulting foam is removed with a piece of filter paper. Carefully, trying not to touch the walls, the urometer plunges into the cylinder. Lab technicians make little effort to optimally position the device. After the oscillations subside, the readings of the urometer are noted on the lower scale.

The calculation takes into account the ambient temperature and makes adjustments. In hot weather, babies drink a lot of fluids, so the urine will be more dilute. Also, children are more mobile than adults, they have a fast metabolism and high vascular permeability. All these factors affect the measurement results.

It is convenient to collect urine for determination of specific gravity in a special container

What indicators of the specific gravity of urine are considered the norm

Normal indicators of the relative density of urine in an adult are 1.01-1.025. Deviation from these parameters even by one division of the urometer scale requires careful further examination. Having ruled out the possibility of a decrease or increase in the specific gravity of urine under the influence of physiological factors (excessive fluid intake), doctors begin to look for the cause of the anomaly.

Immediately after the birth of the child, the first urine sample in his life is taken.

Normal relative density for this age is 1.005-1.017. The newborn has not yet debugged the nutrition system, the water-salt balance has not normalized, and such parameters persist throughout the first month of the baby's life. As the specific gravity increases, the kidneys begin to function actively. The following parameters of urine density are considered within the normal range:

• From one to four years: 1.007-1.016.
• From five to ten years: 1,011-1,021.
• From eleven to fifteen years old: 1.013-1.024.

A low specific gravity of urine is called hypostenuria. The kidneys do not cope with their function of concentrating urine, and it is excreted in a large volume, but with a reduced content of salts and urea.

The increased relative density of urine is called hyperstenuria. The urine excreted during urination is insufficiently diluted, oversaturated with metabolic products. When prescribing further examinations, doctors are also guided by other indicators of biochemical urine tests, for example, the content of leukocytes. Their increased concentration indicates the presence of an inflammatory process in the child's body. Such an infectious focus can significantly affect the parameters of the specific gravity.

The density of urine is not a constant value - it varies throughout the day and depends on the following factors:

• intake of spicy, salty, fatty foods;
• changes in drinking regimen;
• profuse sweat.

Morning urine is the most concentrated, because at night a person does not drink liquid, he does not experience increased sweating. Functional tests are the most informative in detecting pathologies. The child takes urine several times a day at regular intervals. Doctors compare the readings obtained with the help of a urometer and select further diagnostics. For example, if the relative density of urine has not changed in a day, then pyelonephritis can be suspected in the baby.

Diarrhea and vomiting are causes of decreased relative gravity of urine in children

The specific gravity of urine in a child is higher than normal

An increase in the relative density of urine, or hyperstenuria, is often diagnosed in babies who drink little water. Their urine is always too concentrated, its color varies from dark yellow to dark brown. Especially often this happens in the hot season, when there is a natural loss of moisture through increased sweating.

Children get sick much more often than adults. Many of the diseases are accompanied by disorders of the gastrointestinal tract: vomiting and diarrhea. In this case, there is a large loss of fluid, which contributes to an increase in the specific gravity of urine. The indicators also increase in the following cases:

• In children with cardiovascular pathologies, fluid accumulates in the body due to the development of swelling.
• In diabetes mellitus, the specific gravity of urine is significantly higher than normal. The mass of the dry residue increases, as it contains a lot of sugar.
• If a child has infectious diseases, then the proportion increases due to pathogenic microorganisms.

The relative density is always increased in the presence of pathologies of the urinary system. Congenital and acquired diseases of the kidneys, urinary tract and bladder are accompanied by urination disorders and urine stagnation. These symptoms are similar to those of hyperstenuria:

• excretion of a small amount of urine with each urination;
• dark color of urine;
• unpleasant smell of urine;
• the appearance of edema of various localization;
• increased weakness, fatigue, drowsiness, apathy;
• stomach ache.

A high urine density is recorded during antibiotic treatment, as well as with intestinal obstruction. Blunt abdominal trauma can cause an increase in specific gravity.

The specific gravity of urine is determined using a urometer

The specific gravity of urine in a child is below normal

The low relative density of urine in a child can be due to both physiological and pathological causes. Natural factors include:

• After illnesses, especially of infectious origin, doctors recommend that children drink plenty of water to restore the water-salt balance.
• For some diseases of the urinary or cardiovascular system, the child is prescribed diuretics. Under their influence, the volume of urine excreted increases, but the amount of salts dissolved in it is very small.
• After eating some foods, the child may become very thirsty and drink a lot of fluids, which reduces the density of urine.
• The volume of urine is increased, and the number of urination increases when eating watermelons and melons.

Hypostenuria also occurs for pathological reasons. The kidneys lose their ability to thicken urine when removing harmful substances from the child's body. Therefore, getting rid of the body from toxic compounds occurs when large volumes of urine are excreted. The kidneys are under increased strain, filtering a significant amount of blood. This condition requires accurate diagnosis to determine the cause of the pathology.

The specific gravity of the urine of a child will always be reduced in such diseases:

• Polydipsia. With this disease, a person experiences constant thirst and drinks water in large quantities. Sometimes this condition is diagnosed in mentally unstable people; children rarely fall into this category. Pathology often does not need a thorough diagnosis, a description of the symptoms by the parents is sufficient.
• Neurogenic diabetes insipidus. The synthesis of antidiuretic hormone by the pituitary gland is disrupted, and prolonged dehydration develops.
• Nephrogenic diabetes insipidus. The cells of the distal nephron tubule lose their ability to respond to antidiuretic hormone.

You can read more about the causes of low specific gravity of urine.

All these pathologies require immediate treatment, as they provoke serious complications.

Regular laboratory tests help to identify diseases in the early stages, and immediately begin therapy. Urine specific gravity is an important part of the initial diagnosis of pathologies.