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HelpTest ID: UPH24 pH, 24 Hour, Urine
Reporting Name
pH, Urine 24 HourUseful For
Assessment of patients with metabolic acidosis
Assessment of crystalluria
Monitoring the effectiveness of alkalinization or acidification of urine for certain medical conditions (eg, treatment of uric acid nephrolithiasis)
Clinical Information
Urine pH is a measure of the acidity/alkalinity of urine and by itself usually provides little useful information. Under normal conditions its value is influenced by the type of diet. Some diets (eg, diets rich in meat) have more acid content than others (eg, vegetarian diets).
Changes in urine pH may reflect systemic acid-base disorders. For example, the normal response during metabolic acidosis is a lowering of the urine pH to <5. If the pH is >5, then a defect in urine acidification should be considered. A urine pH >7 is suggestive of infection by a urea-splitting organism such as Proteus mirabilis.
Therapeutic interventions to either alkalinize or acidify the urine are necessary for some diseases. For example, some crystals have a propensity to form in alkaline urine, while others form in relative acidic urine, and changing the pH may reduce stone formation.
Interpretation
Dependent on clinical condition
A pH >7 suggests the presence of urinary tract infection with a urea-splitting organism.
Special Instructions
Analytic Time
2 daysDay(s) and Time(s) Performed
Monday through Saturday; 6:30 a.m.-5 p.m.
Method Name
pH Meter
Specimen Type
UrineNecessary Information
24-Hour volume is required.
Specimen Required
Supplies: Diazolidinyl Urea (Germall) 5.0 mL (T822)
Container/Tube: Plastic, 10-mL urine tube (T068) or a clean, plastic aliquot container
Specimen Volume: 10 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Add 5 mL of diazolidinyl urea as preservative at start of collection or refrigerate specimen during and after collection.
3. Refrigerate specimen within 4 hours of completion of 24-hour collection.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 7 days | |
| Frozen | 7 days |
Reference Values
4.5-8.0
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
83986
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| UPH24 | pH, Urine 24 Hour | 27378-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PH24 | pH, Urine 24 Hour | 27378-9 |
| TM90 | Collection Duration | 13362-9 |
| VL72 | Volume | 3167-4 |
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