Chloride is the major extracellular anion that helps maintain fluid balance, osmotic pressure, and acid–base equilibrium.

It works closely with sodium and bicarbonate to regulate blood pH and hydration.

Clinical uses include:

Diagnosing electrolyte imbalances.

Monitoring patients with kidney disease, heart failure, or metabolic disorders.

Evaluating causes of acid–base disturbances (metabolic acidosis/alkalosis).

Supporting assessment in patients with dehydration, vomiting, or diarrhea.

The test is performed using a blood sample, often as part of an electrolyte panel.

Analyte: Serum chloride concentration.

Normal Range: ~98 – 106 mmol/L (varies slightly by lab).

Abnormal Findings:

High chloride (hyperchloremia): May indicate dehydration, kidney disease, metabolic acidosis, or excessive saline infusion.

Low chloride (hypochloremia): May indicate vomiting, metabolic alkalosis, Addison’s disease, or overhydration.

Clinical Use:

Provides insight into fluid and electrolyte status.

Helps differentiate causes of abnormal acid–base balance.

Guides treatment in renal, metabolic, and critical care conditions.