Creatinine: Creatinine, a metabolite of muscle metabolism, is excreted in urine in relatively stable quantities over a 24-hour period. Consequently, urine creatinine can be utilized as an indicator to identify a specimen as urine or to assess the water content (dilution) of urine. Typically, "normal" random urine specimens exhibit creatinine levels greater than 20 mg/dL. Specimens with creatinine levels between 10 and 20 mg/dL may result from increased fluid intake, dietary habits, or liquid consumption preferences. Levels between 2 and 10 mg/dL often indicate the ingestion of substantial volumes of water or other liquids, known as short-term water loading—a common practice to dilute urine and reduce drug concentrations below testing thresholds. Creatinine levels below 2.0 mg/dL suggest the specimen is inconsistent with human urine. Urine creatinine levels are reported alongside drug abuse tests solely to indicate specimen validity; specimens with creatinine levels below 20 mg/dL have a higher likelihood of yielding false-negative drug test results.

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Specific Gravity: Normally, random urine specimens have specific gravity values between 1.003 and 1.035*. Exceptionally low specific gravity (<1.003) indicates a diluted specimen, whereas abnormally high specific gravity (>1.045) may signify the presence of dissolved solids such as sodium chloride and sodium bicarbonate.

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pH: Reference Range = 3–11. Urine specimens with pH values outside this range strongly indicate potential adulteration.

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Visible Blood: This indicates the presence of blood in the urine specimen. The occurrence of blood in the urine sample can negatively affect the testing procedure and also poses a biohazard risk to laboratory personnel. It is advised to collect clean catch urine specimens during menstruation to avoid this issue.