Urine: composition and properties

The product of the vital activity of the body is urine. Its composition, as well as the quantity, physical and chemical properties, even in a healthy person, are impermanent and depend on many innocuous causes that are not dangerous and do not cause any ailments. But there are a number of indicators, determined by the laboratory pathway when passing tests, which indicate a variety of diseases. The assumption that everything is not all right in the body can be done on your own, it's enough just to pay attention to some characteristics of your urine.

How does urine come about?

The formation and composition of urine in a healthy person depends primarily on the work of the kidneys and the loads (nervous, food, physical and other) that the body receives. Every day, the kidneys pass through themselves to 1500 liters of blood. Where so much, because a person on average has only 5 liters? The fact is that this liquid tissue or liquid organ (also called blood) passes through the kidneys about 300 times a day.

With each such passage through the capillaries of the kidney bodies, it is purified from the waste of life, proteins and other substances that are unnecessary to the body. How does this work out? The aforementioned capillaries have very thin walls. The cells that form them work as a kind of living filter. They trap large particles and pass water, some salts, amino acids that seep into a special capsule. This fluid is called the primary urine. Blood enters the tubules of the kidneys, where some filtered substances come back from the capsules, and the remaining ones are discharged through the ureters and the urethra outward. This is a familiar secondary urine for all of us. The composition (physico-chemical and biological, as well as pH) is determined in the laboratory, but some preliminary notes can be made at home. To do this, you should carefully study some characteristics of your urine.

Quantitative indicators

Of the 1,500 liters passed through themselves, the kidneys are rejected about 180. When this filtration is repeated, this volume decreases to 1.5-2 liters, which is an indicator of the norm, in which the amount of urine should be released per 24 hours in a healthy person. The composition and volume of it may vary, depending on:

• Time of year and weather (in summer and in the heat the norm is less);
• Fiznagruzok;
• Age;
• The amount of liquids drunk per day (on average, the volume of urine is 80% of the liquids entering the body);
• Some products.

The deviation of the quantitative norm in one direction or the other can be a symptom of the following diseases:

• Polyuria (more than 2 liters of urine per day) may be a sign of nervous disorders, diabetes, edema, exudates, that is, the discharge of fluids to organs;
• Oliguria (0.5 l of urine and less) occurs with cardiac and renal insufficiency, other kidney diseases, dyspepsia, nephrosclerosis;
• Anuria (0.2 liters or less) - a symptom of nephritis, meningitis, acute renal failure, tumors, urolithiasis, spasms in the urinary tract.

Thus urination can be too rare or, on the contrary, frequent, painful, to increase at night. With all these abnormalities, you need to see a doctor.

Colour

The composition of human urine is directly related to its color. The latter determine the special substances, urochromes, secreted by bile pigments. The more of them, the more yellow and saturated (higher in density) urine. It is considered to be the norm color from straw to yellow. Some foods (beets, carrots) and medications (Amidopyrine, Aspirin, Furadonin and others) change the color of urine to pink or orange, which is also the norm. The test shows the color of urine.

The following color changes determine the following diseases:

• Red, sometimes in the form of meat slops (glomerulonephritis, porphyria, hemolytic crisis);
• Darkening of collected urine in air up to black (alkaponuria);
• Dark brown (hepatitis, jaundice);
• Gray-white (piuria, that is, the presence of pus);
• Greenish, bluish (rotting in the intestine).

Smell

The changed composition of human urine can specify this parameter. So, the presence of diseases can be assumed if the following smells dominate:

• Acetone (a symptom of ketonuria);
• Feces (infection with E. coli);
• Ammonia (means cystitis);
• Very unpleasant, fetid (in the urinary tract there is a fistula in the purulent cavity);
• Cabbage, hops (presence of malabsorption of methionine);
• Sweat (glutaric or isovaleric acidemia);
• Decaying fish (disease of trimethylaminuria);
• "Mouse" (phenylketonuria).

Normally, urine does not have a sharp odor and it is transparent. Also at home you can examine urine for frothiness. To do this, it must be collected in a container and shaken. The appearance of abundant, long-sagging foam means the presence of protein in it. Further, more detailed, analyzes should be carried out by specialists.

Turbidity, density, acidity

In the laboratory, urine is examined for color and odor. Attention is also drawn to its transparency. If the patient has cloudy urine, the composition may include bacteria, salts, mucus, fats, cellular elements, red blood cells.

The density of human urine should be in the range of 1010-1024 g / liter. If it is higher, it indicates dehydration, if lower - about acute kidney failure.

Acidity (pH) should be in the range from 5 to 7. This indicator can fluctuate depending on the person's food and medications. If these reasons are excluded, pH below 5 (acid urine) may mean the patient has ketoacidosis, hypokalemia, diarrhea, lactic acidosis. At pH above 7, the patient may have pyelonephritis, cystitis, hyperkalemia, chronic renal failure, hyperthyroidism of the thyroid and some other diseases.

Protein in the urine

The most undesirable substance affecting the composition and properties of urine is protein. In norm it should be in an adult person up to 0,033 g / liter, that is 33 mg per liter. In infants, this figure can be 30-50 mg / l. In pregnant women, a protein in the urine almost always means some complications. Previously it was believed that the presence of this component in the range of 30 to 300 mg means microalbuminuria, and above 300 mg - macroalbuminuria (kidney damage). Now the presence of protein in the daily urine is determined, and not in a single urine, and its amount up to 300 mg in pregnant women is not considered pathology.

The protein in human urine may temporarily (one-time) rise for the following reasons:

• Postural (body position in space);
• Customs clearance;
• Febrile (fever and other feverish conditions);
• For unexplained reasons in healthy people.

Proteinuria is the protein in the urine in repeated tests. It happens:

• Weakly expressed (protein from 150 to 500 mg / day.) - these are the symptoms that occur with nephritis, obstructive uropathy, acute poststreptococcal and chronic glomerulonephritis, tubulopathy;
• Moderately expressed (from 500 to 2000 mg / day protein in the urine) are symptoms of acute post-streptococcal glomerulonephritis; Hereditary nephritis and chronic glomerulonephritis;
• Sharply expressed (more than 2000 mg / day protein in the urine), indicating that the patient has amyloidosis, nephrotic syndrome.

Erythrocytes and leukocytes

The composition of secondary urine may include a so-called organized (organic) sediment. It includes the presence of erythrocytes, leukocytes, particles of flat, cylindrical or cubic epithelium of cells. For each of them there are norms.

1. Erythrocytes. Normally, men do not, and women have 1-3 in the sample. A small excess is called microhematuria, and a significant excess is called macrogematuria. This is a symptom:

• Kidney disease;
• Pathology of the bladder;
• Discharge of blood into the genitourinary system.

2. Leukocytes. The norm in women is up to 10, in men - up to 7 in the sample. Excess amounts are called leukoceturia. It always indicates the current inflammatory process (disease of an organ). And if the leukocytes in the sample are 60 or more, the urine acquires a yellow-green color, a putrid smell and becomes turbid. Having found leukocytes, the laboratory assistant determines their character. If it is bacterial, it means that the patient has an infectious disease, and if not bacterial, the cause of leukoceturia in problems with the kidney tissue.

3. Cells of flat epithelium. Normally men and women either do not have them, or there are 1-3 in the sample. Excess speaks of cystitis, drug or dysmetabolic nephropathy.

4. Particles of the epithelium are cylindrical or cubic. Normally absent. Excess indicates inflammatory diseases (cystitis, urethritis and others).

Salt

In addition to the organized, the composition of urine analysis determines and unorganized (inorganic) sediment. It is left with various salts, which should not normally be. At a pH of less than 5, the salts can be as follows.

1. Ural (causes - malnutrition, gout). They look like a dense brick-and-pink sediment.
2. Oxalates (products with oxalic acid or diseases - diabetes, pyelonephritis, colitis, inflammation in the peritoneum). These salts are not painted, they look like octagons.
3. Uric acid. This indicator is considered normal at values from 3 to 9 mmol / l. Excess speaks about a renal insufficiency and problems with GASTROINTESTINAL TRACT. It can also be exceeded with stress. Crystals of uric acid are diverse in form. In the sediment they acquire the color of golden sand.
4. Sulfuric acid lime. Rare white precipitate.

At a pH above 7, the salts are:

• Phosphates (the cause is products containing a lot of calcium, phosphorus, vitamin D, or disease - cystitis, hyperparathyroidism, fever, vomiting, Fanconi syndrome); The precipitate of these salts in the urine is white;
• Triphosphate (the same reasons as for phosphates);
• Ammonium urate.

The presence of a large number of salts leads to the formation of kidney stones.

Cylinders

Changes in the composition of urine are significantly affected by diseases associated with the kidneys. Then cylindrical bodies are observed in the collected samples. They form a coagulated protein, epithelial cells from the renal tubules, blood cells and others. This phenomenon is called Celindrarium. Distinguish the following cylinders.

1. Hyaline (coagulated protein molecules or mucoproteins of Tamm-Horsfalla). In the norm of 1-2 per sample. Excess happens at large fiznagruzkah, feverish conditions, a syndrome nephrotic, problems with kidneys.
2. Granular (glued broken cells from the walls of the renal tubules). The cause is severe damage to these kidney structures.
3. Wax (coagulated protein). Appear in the syndrome of nephrotic and in the destruction of the epithelium in the tubules.
4. Epithelial. Their presence in the urine indicates a pathological change in the tubule of the kidneys.
5. Erythrocytes (these are red blood cells clothed hyaline cylinders). Appear with hematuria.
6. Leukocytic (these are layered or blinded leukocytes). Often found together with pus and protein fibrin.

Sugar

The chemical composition of urine shows the presence of sugar (glucose). In the norm it is not. To obtain the correct data, only daily allowances are examined beginning with the second deurination (urination). Detection of sugar to 2.8-3 mmol / day. Is not considered pathology. Excess can be caused by:

• Diabetes mellitus;
• Diseases of endocrinological nature;
• Problems with the pancreas and liver;
• Kidney diseases.

In pregnancy, the sugar in the urine is slightly higher and equal to 6 mmol / day. When glucose is detected in urine, a blood test for sugar is also mandatory.

Bilirubin and urobilinogen

In the composition of normal urine bilirubin is not included. Rather, it is not found because of scanty quantities. Detection indicates such diseases:

• hepatitis;
• jaundice;
• cirrhosis of the liver;
• Problems with the gallbladder.

Urine with bilirubin has an intense color, from dark yellow to brown, and when shaken, a yellowish foam appears.

Urobilinogen, which is a derivative of conjugated bilirubin, is always present in the urine as urobilin (yellow pigment). The norm in the urine of men is 0,3-2,1 units. Ehrlich, and women 0.1 to 1.1 units. Ehrlich (unit of Ehrlich is 1 mg of urobilinogen per 1 decilitre of urine sample). The amount below the norm is a sign of jaundice or is caused by the side effect of certain medications. Exceeding the norm means problems with the liver or hemolytic anemia.