pH, Urine

Test ID: 

703074

CPT code:

83986

Clinical 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.

Additional Informtation:

Dietary factors affect urine pH. Alkaline urine is observed in persons who eat large quantities of citrus fruit and vegetables. Acid urine is observed with high meat intake. Pyridium® metabolites may mask the pH reaction. Urine pH >6.5 indicates presence of bicarbonate while pH <5.5 indicates absence of bicarbonate. Consistently acid urine, pH <5.5, is associated with xanthine, cystine, and uric acid stones. Calcium oxalate and apatite stones are not associated with any particular disturbance of urine pH. Alkaline urine pH >7 is associated with calcium carbonate, calcium phosphate, and especially magnesium ammonium phosphate stones. In conjunction with serum pH and bicarbonate levels urine pH may be applied to the study of renal tubular acidification.

Specimen Type:

Urine (random)

Requested Volume: 

5 mL

Minimum Volume: 

1 mL

Container Type: 

Plastic urine container, no preservative

Patient Preparation: 

Freshly voided random urine

Collection:

Freshly voided random urine

Storage Instructions:

Room temperature

Rejection Criteria:

Preservative added