pH, Urine
Use
The urine pH is a crude measure of the acid-base balance of the body. It may be helpful in determining subtle presence of distal renal tubular disease or pyelonephritis. Urine pH is useful for identifying crystals in urine and determining predisposition to form a given type of stone. See table.
Special Instructions
Dietary factors, such as high intake of citrus fruits and vegetables, can lead to alkaline urine, while a high meat intake can result in acidic urine. Pyridium® metabolites may mask the pH reaction. Freshly voided random urine should be collected for the test, and results may be affected if preservatives are added.
Limitations
This test was developed and its performance characteristics were determined by LabCorp. It has not been cleared or approved by the FDA, which should be considered when interpreting results. The test results for urine pH >6.5 suggest the presence of bicarbonate while pH <5.5 suggests its absence. Urine stones such as xanthine, cystine, and uric acid are associated with consistently acid urine (pH <5.5), while others like calcium oxalate and apatite do not correlate with specific urine pH levels.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 2756-5
- 2756-5
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
1 mL
Container
Plastic urine container, no preservative
Collection Instructions
Freshly voided random urine
Storage Instructions
Room temperature
Causes for Rejection
Icteric samples; preservative added
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |