Indicators of laboratory analysis: urine, pH - norm and deviations. How is the urine pH determined? Where to take the test (pH of urine)?

It is not a secret for anyone that a laboratory examination of body fluids is necessary to accurately diagnose almost any disease. And a fairly clear picture of the state of excretory system gives urine. PH it can help in the diagnosis of inflammatory and infectious diseases.

What is urine pH?

The excretory system of a person is responsible not only for removing excess fluid and toxins from the body, but also provides a normal acid-base equilibrium. It is this criterion that makes it possible to determine urine.

PH is the so-called hydrogen index, which shows the amount of hydrogen ions in the solution (in this case, the solution is a urine sample). This analysis allows you to determine the physical properties of urine, as well as assess the balance of alkalis and acids, which it contains. The results of such studies are extremely important for diagnosis.

What determines this indicator?

In fact, there are many factors that can affect the chemical composition of urine. In particular, pH is largely dependent on human nutrition. In people who use so-called "heavy food", which contains proteins, sulfur and phosphorus, the urine reaction is acidic (less than 5). If the human diet includes mainly vegetable and dairy products, the urine reaction will be alkaline (more than 7).

In addition, there are other factors under the influence of which the urine changes. PH may vary depending on the characteristics of the metabolism. The chemical composition is affected by any inflammatory diseases of the excretory system. The process of digestion also matters, in particular, the decrease or increase in the acidity of the stomach. Some medicines may affect pH.

It is worth noting that the optimal level of hydrogen ions contributes to the normal sanitation of the bladder, and also inhibits the vital activity of pathogenic microorganisms, thereby reducing the likelihood of developing an infectious disease.

When is the urine test prescribed?

To date, the most common sample for research is urine. PH helps determine the presence of a mass of diseases. That is why such tests are prescribed for all patients with suspicion of infectious and inflammatory diseases of the genitourinary system, as well as with a number of other disorders, including metabolic disruptions.

The analysis of urine is prescribed and with annual preventive medical examinations. Sometimes such studies help diagnose the disease even before the appearance of external symptoms.

Samples of urine are recommended to be taken after a previous infectious disease, especially if it is caused by streptococci - this makes it possible to determine the presence of complications.

How to pass urine correctly?

In order for the analyzes to be as true as possible, it is worth following certain rules. The most informative are the samples of morning urine. On the eve it is not recommended to eat food that can change the physical properties of the liquid, in particular carrots and beets. In addition, you should not take diuretics or decoctions, as this can affect the chemical composition of urine.

Before taking samples, it is necessary to wash the genitals - otherwise there will be too many epithelial cells in the samples, which will make laboratory testing more difficult. It is desirable to collect the median urine.

Another important point - you should not conduct such a study for women during menstruation, as menstruation can distort the test results. Only observance of these rules will help to make the urine analysis as accurate as possible - pH will correspond to reality.

How is urine pH determined in the laboratory?

The easiest way to study acid-base balance is the use of special indicators. Most often the urine pH is determined using litmus paper, which changes color depending on the reaction of the solution. Each color corresponds to a certain pH value. This method allows us to determine the index with an accuracy of 0.5.

There are other, more accurate ways by which urine is investigated. PH can be determined using an ionometer (pH meter). This method is more convenient and is characterized by higher accuracy (up to 0.01 units).

Since the pH can vary throughout the day, for greater accuracy, some patients are recommended to measure the pH seven consecutive days.

What is the pH of urine?

Depending on the results of the study, doctors make assumptions about the form and severity of the disease. But what is the normal pH of urine? Again, this indicator depends on the diet, the drugs taken, the age of the patient.

In a healthy person, the urine reaction varies from slightly acid to neutral. Depending on the characteristics of the diet, this indicator can be 4.5 - 8.0.

The pH of urine in newborns is lower and ranges from 4.5 to 5.9. In preterm infants, this figure is lowered even lower - 4.8 - 5.4.

What does the high pH of urine show?

Many people are interested in questions about when alkalinization occurs. As already mentioned, a similar phenomenon is observed when eating vegetable and dairy products, alkaline mineral water. To the same result leads to increased acidity of the stomach and frequent vomiting, which leads to loss of the body's water and chlorine.

On the other hand, there are many diseases in which urine changes. PH increases with many infectious lesions of excretory system. In particular, this happens with cystitis, pyelonephritis and other diseases. It is known that some bacteria cause the decomposition of nitrogen-containing compounds to ammonia, which, in turn, increases the alkalinity of urine.

The same pattern is observed in chronic renal failure. The increase in pH can be caused by the intake of certain drugs, in particular bicarbonates, adrenaline and nicotinamide. The same occurs against the background of hyperfunction of the parathyroid gland, hypoalternosternism and hyperkalemia.

Why does the pH decrease (urine acidification) occur?

Decrease in the hydrogen index and urine acidification occurs with some infectious diseases of excretory system, in particular those caused by the activity of microbacteria of tuberculosis and E. coli.

The cause may be increased acid production in the body. This happens with prolonged starvation, alcohol abuse, sepsis, shock, intense physical activity, diabetes.

Naturally, this change can be caused by taking medications - methionine, ascorbic acid, corticotropin, calcium chloride and ammonium, arginine hydrochloride.

Acidification can be caused by a decrease in the level of bicarbonates in the buffer system of blood, which is observed with severe diarrhea, ureterosigmostomii. Primary and secondary hyperaldosteronism, nephrotic syndrome, hypokalemia, multiple myeloma, cystinosis, poisoning with salts of heavy metals - all these disorders lead to a decrease in the hydrogen index.

Naturally, urine analysis alone is not enough to make an accurate diagnosis. Moreover, not only the pH of the urine, but also the presence of proteins, salts, formed blood cells, etc., is taken into account. Examination of urine is only part of the diagnostic process, which makes it possible to evaluate the work of the excretory system.