A general urinalysis is one of the most accessible, informative, and common laboratory tests. With its help, doctors can assess not only the state of the urinary system but also identify systemic pathologies, including metabolic disorders and chronic kidney diseases [1]. Regular monitoring of basic parameters allows for the timely detection of hidden inflammatory processes and failures in filtration function.
The role of the kidneys in maintaining body balance
The kidneys play a key role in filtering blood, removing toxic metabolic products, and regulating water-salt balance. When renal filtration decreases, for example, due to chronic kidney disease or concomitant cardiovascular pathologies, the composition of urine and blood undergoes significant changes [1]. Modern multiomics and clinical studies emphasize that the state of renal tissue is closely linked to the patient's overall metabolic status, and creatinine clearance levels and the estimated glomerular filtration rate (eGFR) serve as vital prognostic markers [4], [5].
Basic physical and chemical indicators
When interpreting laboratory test results, specialists first evaluate the physical properties of the biomaterial:
- Color and transparency: normally, urine is straw-yellow and clear. Cloudiness or a change in shade may indicate an infection, the presence of salts, or traces of blood.
- Specific gravity (relative density): reflects the concentration capacity of the kidneys. Fluctuations in this indicator indicate disturbances in tubular function.
- Acidity (pH): reflects the acid-base balance. Changes in pH may indicate a predisposition to stone formation or metabolic shifts that affect the entire body [3].
Cellular composition and sediment
Microscopic examination of urine sediment allows for the detection of blood cells and epithelium:
- Erythrocytes: their presence (hematuria) requires the exclusion of trauma, inflammation, urolithiasis, or glomerular pathologies.
- Leukocytes: an increase in their level usually indicates an inflammatory process in the kidneys or bladder (pyelonephritis, cystitis).
- Casts and salts: protein structures (casts) form in the renal tubules and signal serious damage to the renal parenchyma.
Biochemical markers and hidden pathologies
In addition to cellular elements, a standard test evaluates the presence of protein, glucose, ketone bodies, and bilirubin. The appearance of protein in the urine (proteinuria) is often the first sign of a renal filter impairment. In clinical practice, the assessment of renal function also requires a comprehensive approach that considers serum creatinine levels and calculated eGFR indicators, which is especially important for patients with cardiovascular risk factors [4], [5].
Sources
- 1. Multiomics Analysis Identifies Candidate Molecular, Microbiota, and Metabolite Features Associated with Acute Myocardial Infarction Combined with Chronic Renal Failure. PubMed
- 2. Integrative Analysis of Intestinal Transcriptomes Underscores C2 Upregulation in IBD, AIG, EoE, and CRC. PubMed
- 3. A novel corrected anion gap links metabolic acid attack to peptic ulcer disease. PubMed
- 4. Improving the diagnostic performance of troponin assays for acute myocardial infarction in renal impairment. PubMed
- 5. Association of obesity-metabolic indices with heart failure in patients with coronary artery disease. PubMed
Disclaimer: The information provided in this article is for reference purposes only and does not replace an in-person consultation with a nephrologist or general practitioner. If you notice any deviations in your test results, please consult a specialist.