Common analysis of urine: table of average values, interpretation of values, rules of taking

Common or clinical urinalysis is a set of diagnostic tests aimed at studying the physical, chemical and biochemical properties of a patient's urine, its microscopic examination. General analysis of urine is appropriate when there is suspicion of kidney and urinary tract diseases of various etiologies, endocrine disorders, acidosis and alkalosis, dehydration, poisoning, gout, hemolytic anemia, hepatitis and a number of other pathologies, and is also appointed for preventive purposes. The subjects of the study are organoleptic parameters (volume, color, odor, transparency, foam formation), physical and chemical characteristics (density, acidity), biochemical characteristics (protein, bilirubin), sediment composition.

Interpretation of urinalysis results 

Before proceeding to the interpretation of the results of a urinalysis, we must remind you that all the information contained in this article is advisory and introductory nature and can not be used for diagnosis or treatment appointment. Doctor's consultation is mandatory! Now let's look at each of the items in the table and see what may indicate a difference between your results from the reference, that is, from the average statistical indicators. 

Color. A pale-yellow color is considered normal, but even in a healthy person, depending on the diet and other factors, the shade may vary from colorless to amber. The idea of pathology is suggested by a clear change in color. Dark, beer color, up to brown, indicates increased bilirubin or urobilinogen. If it looks like milk, white blood cells are elevated; black urine indicates hemoglobin or myoglobin. Red color is a dangerous sign, hinting at blood excretion with urine; in rare cases bluish-green hues are observed, explained by processes of putrefaction in intestine and subsequent release of special staining substances into blood. 

Smell. Ammonia after urination smells in bacterial infections and inflammatory processes in the urinary system; rotten fruit smells due to an increased concentration of ketones, which is usually a symptom of diabetes mellitus; diabetes can also "smell" of acetone. 

Turbidity. Clouding of the urine is caused by the deposition of salts, crystals, white and red blood cells, the presence of mucus and pus. Expressed filamentous and flaky compounds often accompany pyelonephritis and infection of the lower urinary tract. But also the urine collected for analysis is often turbid due to non-compliance of the laboratory with the conditions of sample storage. 

Foam. If a lot of persistent foam forms when shaken, it hints to the specialist that jaundice may be occurring or that the protein content is elevated. Other explanations could be the patient's poor psycho-emotional state, concussion, impaired circulation in the brain, a neglected form of diabetes, heart failure, and a number of endocrine disorders. 

Relative density. Specific gravity characterizes the ability of the kidneys to concentrate and dilute urine. If the index is outside the lower limits of reference values, it indicates renal insufficiency, polyuria, tubular pathology, or diabetes insipidus of various etiologies. Elevated values of relative density often indicate the development of glomerulonephritis, nephrotic syndrome, diabetes mellitus, dehydration, or become a consequence of intravenous administration of a number of drugs and X-ray contrast agents. 

Acidity. In a healthy person urine reaction is slightly acidic, in the alkaline side (pH > 7) it shifts when using large amounts of products of vegetable and dairy origin, and in the acidic side (pH < 5) - products of animal origin. Pathological acidification of urine is also caused by hypokalemia, diabetes mellitus, gout, and alkalinization - kidney and urinary tract inflammatory or infectious diseases, diarrhea, vomiting. 

Protein. The presence of protein in urine samples - proteinuria - may be a consequence of physical and emotional stress, a symptom of heart failure, arterial hypertension, elevated body temperature, nephroptosis, trauma. Renal filter activity can be impaired by being on your feet for long periods of time, which is why protein sometimes leaks from the blood into the urine in hairdressers, salesmen, military personnel, and people in other professions with sedentary jobs. Renal causes of proteinuria include damage to the tubules and glomerules, and nephrosclerosis. New growths can also make this test item positive. 

Glucose. There should be no glucose in the urine. While a glucose result of about 0.1 mmol/L may be due to an overabundance of sweets in the diet, values of 0.9 mmol/L and above clearly indicate a high probability of diabetes mellitus. Other relatively common causes of glucosuria are pancreatitis, Cushing's syndrome, Fanconi syndrome, and pregnancy. 

Ketones. The appearance of ketones in the tests of a diabetic patient indicates the progression of the disease. In patients without diabetes, ketones are found during fasting, due to a sharp decrease in carbohydrates in the diet or long-term fever. 

Bilirubin. Determination of the amount of bilirubin in the urine becomes possible in cases of liver parenchyma damage, bile outflow disorders, cirrhosis, viral hepatitis and metastasis of neoplasms in the liver. 

Urobilinogen. Traces of urobilinogen in the urine may indicate blood diseases (hemolytic and pernicious anemia, hemolysis, polycythemia, consequences of extensive hematomas), gastrointestinal diseases (inflammatory and obstructive diseases), liver diseases (viral hepatitis, chronic hepatitis, cirrhosis, secondary insufficiency, neoplasms), cardiovascular disorders (myocardial infarction, cardiac and circulatory failure) or intoxication by alcohol, infection or organic compounds. 

Nitrites. Nitrites are not present in normal urine, but their presence indicates infection of the urinary tract. 

Erythrocytes. The correct interpretation of erythrocyturia requires taking into account the history and results of blood tests, since there are many reasons for the increase in erythrocytes. The increase in concentration can have a physiological explanation and be temporary (long standing, strenuous walking and physical activity), can accompany the taking of medications. If the causes of erythrocyturia are still pathological, a specialist may suspect hypertension, diathesis, glomerulonephritis, urolithiasis, pyelonephritis, neoplasm, systemic lupus erythematosus, vasculitis, infectious endocarditis, heart failure, kidney injury or infarction. 

Leukocytes. The level of leukocytes in the urine increases in almost all diseases of the kidneys and urogenital system: all forms of pyelonephritis, glomerulonephritis, cystitis, urethritis, prostatitis, urolithiasis, lupus nephritis, etc. Another explanation could be fever. 

Hemoglobin. Hemoglobin accumulates in the urine in parallel with erythrocyturia, in myositis, massive muscle tissue damage, thrombosis in muscle vessels, myocardial infarction, hemolytic anemia, burns, mushroom and phenol poisoning. 

Epithelium. A distinction is made between elements of squamous cell, transitional cell, and renal epithelium. Appearance/enhancement of squamous epithelium cells is observed in urinary tract infection, transitional epithelium - in cystitis, pyelonephritis and urolithiasis, renal epithelium - in glomerulonephritis, pyelonephritis, poisoning with heavy metal salts, renal circulatory pathology. 

Cylinders. Detection of hyaline cylinders in the urine indicates renal pathology, heart failure, or overheating (fever, heat stroke, sunstroke). In some cases, they are found after excessive physical activity, taking diuretics and exacerbations of arterial hypertension. Waxy cylinders are excreted with urine in glomerulonephritis, pyelonephritis, diabetic nephropathy, viral diseases, fever, and lead intoxication. Increased waxy cylinders indicate amyloidosis, renal failure, or nephrotic syndrome. 

Salts. Almost absent in the urine of a healthy person, their appearance hints at a violation of mineral metabolism, development of urolithiasis, nephrolithiasis, dehydration of the body, chronic renal failure. 

Mucus. The content of mucus in the sample is most often explained by a trivial violation of the rules of urine collection. But also mucus is actively excreted with the urine in inflammatory processes. 

Bacteria, fungi, parasites. Their appearance in the urine is explained by the corresponding disease of the urinary tract. 

How to prepare and take a urine sample 

1. The day before urine collection, you should avoid foods containing strong natural dyes: beets, blueberries, carrots, etc. It is also recommended to refrain from alcohol, coffee and strong tea.
2. On the eve of taking the sample it is worth refraining from visiting baths and saunas, from heavy physical exertion and from taking diuretics (possibly after consulting a doctor).
3. Women are not recommended to take the test during menstruation, as even minor traces of blood in the urine can make the test results inconclusive.
4. If you are taking medication, it is worth notifying your doctor or lab technician about the medications you are taking. Similarly, you should do this if you have undergone invasive examinations or procedures on the urinary tract in the week before the collection of urine.
5. At the laboratory, a urine sample should be brought in a special disposable sterile container, which is cheap and can be purchased at any pharmacy. But samples from glass containers will simply not be accepted at the laboratory.
6. If you have not received any other instructions from your doctor, the first morning portion of urine is collected in order to perform the tests. A small amount should be released into the toilet and then, without stopping urination, collect about 50 ml of urine in a container. Try to avoid contact of the sterile container with skin and mucous membranes.
7. Before collecting the urine you should take a shower with hygienic treatment of the external genitalia, but without the use of antibacterial and disinfectants.
8. It is not recommended to stimulate urination by taking copious amounts of water, tea and other diuretic fluids - this can affect the results.
9. Severe emotional stress can affect the results.
10. High blood pressure can also cause inaccuracies in the test.