pH, Urine

Urine pH, pH, Urine by Meter, UPH

Test Codes

EPIC: LAB2111145

Department

Chemistry

Instructions

Please refer to the Specimen Collection Manual for instructions on 24-Hour Urine Collection:

• Urine 24-Hour Collection - Inpatient
• Urine 24-Hour Collection - Outpatient
• Urine 24-Hour Collection - Outreach

Specimen Collection Criteria

Collect (preferred specimen): Random urine specimen in a screw-capped container (preferred) or other sterile collection cup. (Minimum: 0.2 mL)
Also acceptable: 24-hour or timed urine specimen with no preservatives.

• Refer to the table of Urine Preservative Options when multiple tests are requested.
• Keep 24-hour urine specimen iced or refrigerated during collection.
• Include start and end dates and times for the collection period on the specimen container.

Urine Preservative Options
No Preservative	6N Hydrochloric Acid	Boric Acid (10g)	Sodium Carbonate	50% Acetic Acid
Required	Unacceptable	Unacceptable	Unacceptable	Unacceptable

Physician Office/Draw Specimen Preparation

Maintain specimens capped (to prevent pH changes) and refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport: Random urine, or entire 24-hour or timed urine collection, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

Specimens not collected and processed as indicated. 

In-Lab Processing

Keep specimen capped to prevent pH changes. Measure total volume of 24-hour or timed urine specimen. Record total volume and collection start and end dates and times in the LIS system. Aliquot a minimum of 10.0 mL from the well-mixed 24-hour or timed urine collection.

Storage

Specimen Stability for Testing:

Room temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): For longer storage.

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days (Royal Oak and Troy store an aliquot for 30 days.)

Laboratory

Canton Chemistry Laboratory
Dearborn Chemistry Laboratory
Farmington Hills Chemistry Laboratory 
Grosse Pointe Chemistry Laboratory 
Lenox Laboratory
Livonia Laboratory
Royal Oak Automated Chemistry Laboratory 
Troy Chemistry Laboratory
Taylor Chemistry Laboratory
Trenton Chemistry Laboratory
Wayne Chemistry Laboratory 

Performed

Sunday – Saturday.
Results available within 24 hours.

Reference Range

4.5 – 8.0.

Test Methodology

pH test strip and automated urine analyzer.

Interpretation

• 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 (e.g., diets rich in meat) have more acid content than others (e.g., 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 less than 5. If the pH is greater than 5, then a defect in urine acidification should be considered. A urine pH greater than 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.

CPT Codes

83986

Contacts

Last Updated

8/15/2025