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Analysis of urine

, medical expert
Last reviewed: 24.06.2018
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A general urine test is a study conducted in a special laboratory and assigned to a patient in the process of diagnosing a disease. The analysis of urine consists of the following stages:

  • Organoleptic study - includes analysis of the amount of urine, its color, odor, foam and transparency.
  • Physico-chemical analysis of urine - makes it possible to determine the specific gravity and acidity level of urine.
  • Biochemical analysis of urine is carried out to detect protein in the urine.
  • Microscopic analysis of urine allows you to determine the extent of the presence of red blood cells and leukocytes.

It is the data obtained in the analysis of urine that serve to recognize chronic nephropathies, especially those that occur latently, and also to assess the activity and, when performing in dynamics, the rate of progression of kidney damage and the response to ongoing therapy.

trusted-source[1], [2], [3], [4]

Collection of urine

Examine the average portion of morning urine. Microscopy should be performed no later than 2 hours after collection of urine. If immediate microscopy is not possible, urine should be stored at low temperatures to prevent bacterial growth and lysis of cell elements (erythrocytes, white blood cells, cylinders). To maintain the integrity of red blood cells and leukocytes, deliberately alkaline urine is acidified. If it is impossible to comply with the rules for collecting urine, for example in patients with impaired consciousness, it is recommended to perform a catheterization of the bladder.

trusted-source[5], [6], [7], [8], [9], [10], [11]

How can I take a urine test?

Morning urine is usually taken for analysis. Before emptying the bladder, you must necessarily perform an intimate hygiene procedure using soap. The urine should be drained into a plastic container, which is sold in a pharmacy. Urinalysis is usually performed no later than an hour and a half after the collection of urine. Before taking a urinalysis, it is forbidden to take medications, since this can affect the results, and urine should not be left at sub-zero temperature.

Urinalysis by Nechiporenko

Analysis of urine by Nechiporenko allows to detect inflammatory processes occurring in the urinary tract and to determine the level of leukocytes, erythrocytes and cylinders. Normally, the following indicators are allowed: leukocytes - up to 2000 ml in males and up to 4000 ml in females; erythrocytes - up to 1000 ml; cylinders - up to 20 ml. Before you take the urine, you must first prepare a dry plastic container, which then need to collect about 200 ml of morning urine (a minimum of fifty to one hundred milliliters). The urine is analyzed as follows: the collected urine is shaken, then taken a little to a test tube that is centrifuged for several minutes, then the upper part of the urine is collected, and in the test tube, 1 milliliter of urine is left with the precipitate, which is thoroughly mixed and placed in a special chamber, leukocytes, erythrocytes and cylinders.

Urinalysis during pregnancy

At the onset of pregnancy, women have to take urine tests almost every week. The genitourinary system of a pregnant woman undergoes double the load, because during pregnancy not only does the uterus increase, but there is a compression on the kidneys, the bladder associated with the growth and location of the fetus. Therefore, the delivery of urinalysis during pregnancy is a mandatory regular procedure. For pregnant women, a small amount of protein in the urine may be the norm, although there is no protein in the urine in the usual state. If more than three hundred mg of protein is found in the urine of a pregnant woman, it can signal kidney pathologies, including chronic ones, that could become worse during pregnancy. In such cases, inpatient treatment is prescribed. Proteinuria (protein in the urine), which occurs at the 32nd week of pregnancy, can signal the development of nephropathy, accompanied by increased blood pressure, impaired functioning of the placenta. In the urine of pregnant women, various bacteria are often found. Bacteriuria can cause the development of pyelonephritis, which can cause a threat of premature birth. Of particular importance is the analysis of urine with asymptomatic bacteriuria, since only in this way can reveal hidden pathologies. In the urine of pregnant women there should be no leukocytes, and disorders of the genitourinary system can be indicated by an elevated level of salt content. If ketone bodies were detected in the urine of a pregnant woman, this may indicate the development of toxicosis. With a lack of potassium, as well as toxicosis in urine, the acidity level can be lowered. Urine analysis during pregnancy includes examination of color and transparency, density, epithelium, bilirubin, erythrocyte and cylinder contents. In case of receiving unfavorable results, additional urine tests are prescribed - according to Nechiporenko's method, as well as bacussia of urine, etc.

Microscopy of urinary sediment

Investigation of the constituent elements of urinary sediment is of great practical importance, including for establishing the level of localization of the pathological process in the urinary system. Elements of the urine sediment are divided into organic (cellular elements, cylinders) and inorganic (crystals of different salts).

Among organic elements of the urine sediment, epithelial cells, erythrocytes, leukocytes and cylinders are examined.

Epithelial cells

Epithelial cells differentiate according to the type of epithelium. Cells of flat epithelium originate from the lower parts of the urinary tract; increasing their content more than 1-2 in the field of vision, especially a large number of them indicates inflammatory processes in the bladder or urethra. The source of cells of the cylindrical epithelium is the renal pelvis and ureter; an increase in their number is observed with pyelonephritis and urethritis. The cells of the renal tubular epithelium are rounded, their detection in complexes with the cylinders or in large groups testifies to their renal origin. This type of cells is found in various kidney diseases (tubulointerstitial nephritis, chronic glomerulonephritis, including lupus).

trusted-source[12], [13]

Erythrocytes

Erythrocytes are found in the urine sediment of healthy individuals in an amount of 0-1 in the field of vision.

The presence of a macromemuria in a patient is judged by a characteristic change in the color of urine; to distinguish it with myoglobinuria and hemoglobinuria, there are special tests ("Hematuria").

trusted-source[14], [15], [16], [17], [18], [19], [20], [21]

Leukocytes

Leukocyturia - an increase in the content of leukocytes in the urinary sediment (the norm is 0-1 in the field of view of the microscope in men and up to 5-6 in women). Differential diagnostic tests to determine the leukocyte population of the urinary sediment are used to accurately determine the source of leukocyturia.

Isolate infectious leukocyturia, characteristic of many infectious and inflammatory diseases of the urinary system (including pyelonephritis). About the infectious nature of leukocyturia can be tentatively judged by the detection in the urinary sediment of bacteria - bacteriuria (more than 1x10 5 / ml of urine). During the sowing, urine often results in false negative results due to the fact that even the insignificant violations of the rules for sampling and storage of samples affect the accuracy of this method. Aseptic leukocyturia, characteristic of many forms of chronic glomerulonephritis, analgesic nephropathy; sometimes observed in amyloidosis.

Cylinders

Cylinders are formed by the connection of the Tamm-Horsfall Uromucoid (protein secreted by the epitheliocytes of the ascending knee of the Henle loop), plasma proteins that have passed through the glomerulus membrane and specific constituents (cells, fat particles).

  • Hyaline cylinders consist only of protein molecules, they are found in various kidney diseases and normal (not more than 100 in 1 ml of urine).
  • Waxy cylinders consist of plasma proteins and act as a sign of chronic nephropathy.
  • Cellular cylinders (erythrocyte, leukocyte) always have a renal origin and indicate a lesion of the kidney parenchyma.
  • Fatty cylinders are found with significant proteinuria, including nephrotic syndrome.
  • Grainy cylinders are a sign of kidney disease.

trusted-source[22], [23], [24], [25], [26]

Inorganic elements of urine sediment consist of crystals of different salts

Detection of uric acid crystals, calcium oxalate, amorphous urates and phosphates, as well as triphosphate in the urine is not a sign of kidney damage, urine analysis and clinical data should be taken into account.

The presence in the urine of crystals of cholesterol, cystine, tyrosine and leucine always indicates the defeat of the kidneys. Cholesterol crystalluria is observed in patients with nephrotic syndrome; crystals of tyrosine and leucine indicate prognostically unfavorable liver damage.

In the urinary sediment, bacteria, fungi, protozoa and parasites are also found. Bacteriuria is most significant in combination with leukocyturia; to clarify its genesis, it is advisable to conduct a bacteriological study of urine. Of the fungi in the urinary sediment are most often found representatives of the genus Candida, especially in patients with diabetes mellitus or receiving immunosuppressive therapy. Sometimes amoebae are found; In the presence of dysuria, this indicates a genito-urinary amoebiasis. Detection of eggs Schistosoma haematobium indicates the invasion of the urinary tract.

trusted-source[27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37]

General urine test: normal

Normal color of urine varies from light yellow to dark yellow. Too intense yellow color usually indicates an increased density of urine, which is usually observed during dehydration, too light urine, on the contrary, indicates that the density is low. This means that there is a chance of kidney failure. Any changes in the color of urine from pale pink to dark-brown color can be indicators of serious pathological processes. At the same time, some drugs, as well as abundant consumption of beets and carrots, can affect urine coloration. If the analysis found that the urine is not transparent, this can be explained by the presence in it of bacteria, red blood cells, salts, fat, mucus, etc. If the urine is shaken, foam appears on it. If the foam is cloudy, abundant and persistent, it can mean that there is protein in the urine. Normally, the foam is clear and quickly soluble. If the urine protein level is more than 0.033 g / l, this is considered a deviation from normal indicators.

Interpretation of urinalysis

Urine analysis includes evaluation of the following parameters.

  • Color, transparency.
  • Relative density.
  • Chemical tests:
    • pH;
    • protein;
    • glucose;
    • ketone bodies;
    • hemoglobin (determined, as a rule, with a corresponding change in the color of urine);
    • urobilinogen;
    • Myoglobin (determined, as a rule, with a corresponding change in the color of urine).
  • Microscopy:
    • crystals - urate, phosphate, oxalate or calcium carbonate, tripolphosphate, cystine, medicinal;
    • cells - leukocytes, erythrocytes, tubular epithelium cells, urinary tract, atypical cells;
    • cylinders - hyaline, granular, erythrocytic, leukocytic, epithelial, waxy, granular, lipid;
    • infectious agents - bacteria, fungi, parasites.

Urine analysis implies mandatory determination of protein content, cellular elements (erythrocytes, leukocytes), bacteria and some other indicators. In addition, with the help of additional methods of research in urine, active forms of leukocytes are detected, as well as the content of chemokines, growth factors and vasoactive molecules.

To diagnose microalbuminuria, a standard rapid test is used, which allows monitoring of its magnitude, including in outpatient settings.

Color and clarity of urine

Freshly picked urine is normally clear. The cause of turbidity of urine is established with the help of additional tests.

  • The disappearance of turbidity after heating urine to 60 ° C indicates an excessive content of urate and uric acid in it.
  • If urine becomes transparent after the addition of 10% acetic acid, then there is an excess of phosphates.
  • With an excess of oxalates, the turbidity disappears after the addition of dilute hydrochloric acid.
  • If there is a large number of elements or mucus in the urine, it becomes transparent only after filtration and centrifugation.
  • Resistant to all qualitative tests and centrifugation, turbidity indicates bacteriuria.
  • On the surface of urine containing a large amount of protein, a persistent foam is formed.

The urine of a healthy person is straw-yellow, the intensity of the color depends on the degree of its dilution. The urine of a patient with chronic renal insufficiency is almost colorless. The change in the color of urine is also due to the presence in it of various chemicals, including drugs and their metabolites, as well as pus, blood and lymph.

trusted-source[38]

Causes of a change in color of urine

Colour

Cause

White

Red / Pink / Brown

Yellow orange

Brown / Black

Green, blue

Lymph, pus, crystals of phosphate

Erythrocytes, hemoglobin, myoglobin, porphyrins, levodopa, methyldopa, metronidazole, phenacetin, phenolphthalein, food colorings

Bilirubin, urobilin, iron preparations, nitrofurantoin, riboflavin, sulfasalazine, rifampicin, phenytoin

Methemoglobin, homogenzitinovaya acid (with alkaponuria), melanin (in patients with melanoma)

Biliverdin, dyes (methylene blue and indigo carmine), triamterene, B vitamins, indikan, phenol, chlorophyll, infection with Pseudomonas aeruginosa

Milky white color of urine is due to the ingress of a large amount of lymph or fat into it. Massive excretion of salts of uric acid causes orange (brick) or brown color of urine. When porphyria urine darkens when standing in the air.

A correct interpretation of the red color of urine is necessary. Fresh blood stains the urine in scarlet color, hematuria of renal origin gives the urine a characteristic appearance of "meat slops" - one of the signs of glomerulonephritis, including acute, myoglobin - red-brown color. In addition, the red color of urine is noted with the use of methyldopa, phenothiazine derivatives.

trusted-source[39], [40], [41], [42]

The smell of urine

Urine has a characteristic odor. Its change occurs in various diseases, including metabolic diseases.

Causes of a change in the smell of urine

Smell

Cause

Sweet, rotting fruit

Ketone bodies

Ammonia

Infection of the urinary tract with urea-degrading bacteria

Moldy

Phenylketonuria

Sweat

The presence of isovaleric or glutaric acids in the blood

Rancid fat

Hypermethioninemia, tyrosinemia

trusted-source[43], [44], [45], [46], [47], [48], [49], [50]

Acidity of urine

The urine reaction varies widely (pH 4.5-8.5). A re-alkaline reaction of urine testifies to the possibility of infection of the urinary tract or renal tubular acidosis.

trusted-source[51], [52], [53], [54], [55], [56]

Relative density of urine

Relative density of urine in a healthy person varies from 1.002 to 1.030. This indicator depends on the diet and the regime of fluid intake. Depression of relative urine density is an early sign of tubulointerstitial nephritis and chronic renal failure. To accurately determine this indicator, it is necessary to carry out the Zimnitsky trial. With an increase in the protein content in urine by 4 g / l or glucose by 2.7 g / l, this index increases by 0.001.

Urinalysis in children: transcript

At the general analysis of urine in children such parameters as coloring, a smell, a transparency, specific weight, level of erythrocytes and leukocytes, presence of protein, sugar, ketone bodies, salt, bacteria, mucus are taken into account. Normal indicators are the absence of an atypical odor in the urine and opacities. If the urine has a smell of ammonia, it can signal a malfunction with the bladder. The acidity level in the baby's urine ranges from 4.8 to 7.5. With diarrhea, vomiting, and the prevalence of plant food and physical overstrain in the diet, an alkaline reaction occurs. The increased acidity of urine is observed at a temperature, diabetes or excessive consumption of protein in the food. Normal indicators of urine density are in dependence on age from 1.003-1.025. Protein, sugar, erythrocytes, cylinders, bacteria, salts and ketone bodies in the urine of the child should not be. Such components can appear with metabolic disorders, kidney, bladder, endocrine system, vomiting, fever, diarrhea, constipation, nervous overstrain, anemia. An increased white blood cell count may occur in inflammatory processes of the urinary system.

General analysis of urine: transcript

Normal indicators for a healthy person:

  • Color - a moderate yellow, not too saturated, but not too pale.
  • Transparency is the norm.
  • The smell is unsharp.
  • Acidity - pH less than 7.
  • The density is from 1.018.
  • Protein is not.
  • Ketone bodies are not.
  • Bilirubin - no.
  • Urolilinogen - five to ten mg / l.
  • Hemoglobin - no.
  • Erythrocytes - from zero to three in the field of vision for female, from zero to one in the field of vision for men.
  • Leukocytes - from zero to six in the field of view in women, from zero to three in the field of vision in men.
  • Epithelium - from zero to ten in the field of view.
  • Cylinders - no.
  • Salt - no.
  • Bacteria - no.

It is important to know!

Forced diuresis as a method of detoxification is based on the use of drugs that contribute to a sharp increase in diuresis, this is the most common method of conservative treatment of poisoning, in which excretion of hydrophilic toxicants is performed primarily by the kidneys. Read more..

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