urinepH

Urine pH is a measure of the acidity or alkalinity of urine, expressed on the pH scale from 0 to 14, with 7 as neutral. In healthy adults, urine pH typically ranges from about 4.5 to 8.0, with an average around 6.0. pH can be measured using urine test strips or a calibrated pH meter in a laboratory. A single measurement provides a snapshot, and results can vary with time of day and recent meals or fluid intake.

Several factors influence urine pH. Diet is a common determinant: high-protein, meat-heavy diets tend to produce more acidic urine, while vegetarian or fruit-rich diets can raise pH. Medications such as bicarbonate, acetazolamide, or certain diuretics can increase pH, whereas agents like ammonium chloride or ascorbic acid can lower it. Urinary tract infections caused by urease-producing bacteria can elevate pH. Persistent alkaline urine may indicate renal tubular disorders or metabolic disturbances, while persistently acidic urine can be seen in dehydration or metabolic acidosis. Stone risk varies with pH: uric acid stones form in acidic urine, calcium phosphate stones in alkaline urine.

Clinical use and interpretation: Urine pH is evaluated in planning stone prevention, diagnosing metabolic or renal disorders, and monitoring treatment. A single abnormal pH value is not diagnostic; trends over time and correlation with clinical data are important. Sample handling can affect pH; delayed testing or contamination can alter results. In stone formers, clinicians may target a specific urinary pH using diet, medications, or supplements to reduce recurrence risk.