Daily urine analysis: collection rules, interpretation of results
The content of the article:
- Preparation for analysis
- Collection of daily urine for analysis
-
Deciphering the main indicators: norm and deviations
- Volume
- Protein
- Glucose
- Oxalates
- Cortisol
- Catecholamines
- Calcium
Daily urine analysis, that is, a laboratory study of urine collected per day, makes it possible to obtain information about the state of the body and the metabolic processes occurring in it. As a rule, the analysis is carried out as part of a clarifying diagnosis, but during pregnancy it can also be prescribed for prophylactic purposes.
Preparation for analysis
When prescribing an analysis, you should consult a doctor who will tell you how to properly prepare, how to collect daily urine for analysis and where to take the analysis. The fact is that the rules for preparing and collecting material may vary depending on which indicator is being researched. After receiving the result, only a specialist, based on the complete diagnostic data, will be able to decipher what this or that indicator shows.
Daily urine analysis is performed if you suspect a urinary tract disease, metabolic disorders Daily urine analysis is performed if you suspect a urinary tract disease, metabolic disorders
On the eve of the study, it is advisable to stop eating foods that can change the color of urine (for example, beets, blueberries, etc.), as well as eating fatty, salty, spicy foods and alcohol. In general, the usual diet, like the drinking regime, does not need to be changed - with some exceptions. So, before analyzing daily urine for catecholamines, it is not recommended to eat dairy products, bananas, chocolate, cheese. Before testing for oxalates - acidic foods.
In case of taking medications, you should consult with your doctor about the need to cancel them for the period of preparation for the analysis. In particular, three days before the study for catecholamines, it is advisable not to take medications containing caffeine, ethanol, nitroglycerin, theophylline.
In addition, on the eve of collecting daily urine for analysis, it is necessary to exclude significant physical and psycho-emotional stress, smoking, the action of painful stimuli.
Urine analysis is undesirable during physiotherapy, after invasive procedures, as well as for women during menstruation.
In advance, you should prepare a container into which the biological material will be collected. You can purchase a special container for daily urine at the pharmacy or in the laboratory when making an appointment for an analysis, it is convenient to use, since it does not require any preliminary processing. If this is not possible, you should prepare a three-liter glass jar: wash it thoroughly, and then sterilize over steam and dry it. In some cases (indicated by the doctor when referring to the analysis) it is necessary to add a preservative to the container, which is also purchased at the pharmacy or issued in the laboratory.
Collection of daily urine for analysis
On the day of collecting the material, the first morning urine is not collected, it is released into the toilet. All the rest of the urine during the day and the first morning urine of the next day is collected in one container, which during the collection of the material should be stored in a dark cool place at a temperature of 4 to 8 ° C (cannot be frozen).
In some cases, it is necessary to deliver all the collected urine to the laboratory, in others a small portion of it is sufficient. In the latter case, after receiving the last (next morning) portion, record the volume of the collected material, then, gently shaking, mix, pour 50–100 ml into a small container and transport it to the laboratory as soon as possible.
If it is necessary to collect daily urine from an infant, use specially designed urine bags, from which urine is drained into one container.
Deciphering the main indicators: norm and deviations
In the course of biochemical analysis in daily urine, the quantitative content of creatinine, glucose, proteins, oxalates, urea, hormones is determined - depending on the reason for the study.
Volume
Normally, an adult produces about 1-2 liters of urine per day. Its amount depends on age, drinking regime, ambient temperature, as well as the presence of pathologies. If less than 0.5 liters of daily urine is released, they talk about oliguria, if more than 3 liters, about polyuria.
The causes of oliguria can be physiological (insufficient fluid intake, intense physical activity) and pathological, for example, urinary stagnation or renal failure.
Polyuria can be a consequence of dysfunction of the thyroid gland, liver, deterioration of the filtration function of the kidneys.
Protein
Normally, the amount of protein should not exceed 140 mg / day, after significant physical activity - no more than 250 mg / day. The excretion of protein in the urine in excess of normal amounts is called proteinuria.
Functional proteinuria accompanies fever, hypothermia, congestive heart failure, and some acute diseases. Such proteinuria disappears after the elimination of the etiological factor and the normalization of the state of the body.
By origin, proteinuria is:
- prerenal - an increase in the concentration of plasma proteins;
- renal - caused by kidney pathologies;
- postrenal - caused by diseases of the urinary tract.
The study of protein in daily urine is prescribed for suspected endocrine disorders (diabetes mellitus, hyperthyroidism, etc.), benign or malignant tumors of the urinary system and liver, cardiovascular diseases, infective endocarditis, as well as for violations of intestinal motility, drug overdose.
The loss of large amounts of protein in the urine is usually due to glomerular filter dysfunction. Increased protein content in daily urine is observed with damage to the renal tubules, glomerulonephritis, diabetic nephropathy, nephrotic syndrome, lymphoproliferative or myeloproliferative diseases, urinary tract infections, neoplasms of the urinary system, congestive heart failure, excessive physical exertion.
Non-steroidal anti-inflammatory drugs can overestimate the result of a daily urine test for protein (false-positive results), and angiotensin-converting enzyme inhibitors can underestimate.
Glucose
An analysis for sugar in urine (as the definition of glucose level is called in everyday life), as a rule, is carried out with suspicion of diabetes mellitus, thyrotoxicosis, pheochromocytoma, Itsenko-Cushing's disease, myocardial infarction, the addition of a secondary bacterial infection in case of extensive burns or injuries.
The study of the glucose content of daily urine is carried out as part of the diagnosis of diabetes The study of the glucose content of daily urine is carried out as part of the diagnosis of diabetes
Normally, the level of glucose in the urine should not exceed 1.6 mmol per day.
Oxalates
An analysis for oxalic acid salts (oxalates) in daily urine is usually prescribed when an increased indicator is obtained in the general urine analysis. Normally, it is about 650 mmol per day.
An increased content of oxalates in urine is observed in urolithiasis, inflammatory processes of the digestive tract, malignant neoplasms of bones, endocrine pathologies. Decreased levels of oxalate in daily urine may indicate a vitamin D deficiency in the body.
Cortisol
Cortisol is a hormone of the adrenal cortex responsible for the formation of the body's response to stress and is involved in the metabolism of carbohydrates. Since it is not secreted with every urination, a cortisol test requires 24-hour urine. The norm is 100-380 nmol / day.
An increase in the level of cortisol in the urine may indicate a pathology of the adrenal cortex, hypercortisolism, and Itsenko-Cushing's disease. Decrease - for Addison's disease, liver cirrhosis, hypothyroidism, pituitary tumor.
Catecholamines
Catecholamines (physiologically active substances in the blood) are characterized by a short period of existence. Intermediate metabolites of catecholamines include metanephrines, normetanephrines. When analyzing daily urine for catecholamines, metanephrines and final metabolites, the likelihood of obtaining false positive results is significantly reduced.
The analysis of daily urine for catecholamines is carried out as part of the diagnosis of adrenal neoplasms.
Calcium
The analysis of daily urine for calcium is used to diagnose rickets in infants, pathologies of bone tissue, pituitary gland, thyroid gland.
The rates of this indicator depend on age. For adults, normal values are from 2.5 to 7.5 mmol / day, for children - no more than 10.5 mmol / day.
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Anna Aksenova Anna Aksenova Medical journalist About the author
Education: 2004-2007 "First Kiev Medical College" specialty "Laboratory Diagnostics".
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