Chloride is an essential electrolyte that works with sodium and potassium to maintain fluid balance, blood pressure, and acid–base equilibrium.

The 24-hour urine test provides an accurate measure of chloride excretion compared to a random urine sample.

Clinical uses include:

Assessing kidney function and tubular handling of chloride.

Investigating causes of metabolic alkalosis or acidosis.

Monitoring patients with hypertension, adrenal gland disorders, or diuretic therapy.

Evaluating dietary chloride intake and excretion balance.

The test requires collecting all urine passed in 24 hours in a special container.

Analyte: Chloride concentration in 24-hour urine.

Normal Range: Approximately 110–250 mmol/24 hrs (varies by lab and diet).

High Chloride Excretion: May indicate excessive salt intake, renal tubular disorders, or metabolic acidosis.

Low Chloride Excretion: May suggest metabolic alkalosis, adrenal insufficiency, dehydration, or chloride-losing nephropathy.

Clinical Use:

Detects abnormalities in chloride metabolism.

Differentiates renal vs non-renal causes of electrolyte imbalance.

Supports diagnosis of endocrine, renal, and acid–base disorders.