24-hour Urine Analysis.
24-hour urine analysis (24-hour diuresis) is a laboratory test aimed at evaluating kidney function and overall body condition by collecting all urine excreted over 24 hours. This analysis allows determination of the total urine volume and concentration of various substances, helping to identify water-electrolyte balance disturbances, kidney function, and metabolic disorders.
Goals and significance of the analysis:
- Evaluation of total urine volume over 24 hours (24-hour diuresis), important for diagnosing kidney diseases, cardiovascular system disorders, and endocrine abnormalities.
- Determination of concentrations in urine of substances such as protein, glucose, creatinine, urea, electrolytes, calcium, sodium, potassium, and others.
- Detection of impairments in the kidneys’ concentrating and excretory functions.
- Diagnosis and monitoring of kidney diseases, diabetes mellitus, hypertension, metabolic disorders, and other pathologies.
Indications for the test:
- Suspected chronic renal failure and other kidney diseases.
- Evaluation of kidney function in diabetes mellitus, hypertension, heart failure.
- Water-electrolyte balance disturbances (edema, dehydration).
- Monitoring treatment effectiveness for kidney and metabolic diseases.
- Identifying causes of polyuria (increased urine output) or oliguria (reduced urine output).
How to properly collect 24-hour urine:
- Start collection in the morning after the first urination (this urine is not collected).
- Then collect all urine excreted over the next 24 hours, including the first morning urination of the following day.
- Collect urine in a clean, preferably sterile container stored in a cool place (e.g., refrigerator).
- At the end of collection, thoroughly mix the entire urine volume and pour out the required amount for laboratory analysis.
- Accuracy and completeness of collection are vital to obtain reliable results.
Preparation for the analysis:
- Avoid physical exertion, alcohol, and foods affecting urine color and composition for 24 hours before collection.
- Maintain a normal lifestyle and diet during the collection period.
- Fluid intake should be usual unless otherwise instructed by a doctor.
Interpretation of results:
- The typical total urine volume for an adult is 1–2 liters; deviations may indicate pathology.
- Increased diuresis (polyuria) may indicate diabetes mellitus, kidney diseases, or endocrine disorders.
- Decreased diuresis (oliguria) is found in renal failure, dehydration, heart failure.
- Substance concentrations in urine help assess kidney function and metabolism.
- Test results are always interpreted by a physician taking into account the patient’s clinical picture.
Thus, 24-hour urine analysis is an important diagnostic tool for a comprehensive assessment of kidney function and overall body condition.