Bicarbonate is a key component of the body’s buffer system, helping maintain normal blood pH.

It reflects the metabolic component of acid–base balance.

Clinical uses include:

Diagnosing metabolic acidosis (low bicarbonate) and metabolic alkalosis (high bicarbonate).

Assessing respiratory disorders (compensatory changes in bicarbonate).

Monitoring patients with kidney disease, diabetes, or critical illness.

The test is performed using a blood sample, often as part of an electrolyte panel or arterial blood gas (ABG) analysis.

Analyte: Serum bicarbonate concentration.

Normal Range: ~22 – 29 mmol/L (varies slightly by lab).

Abnormal Findings:

Low bicarbonate: Suggests metabolic acidosis (e.g., kidney disease, diabetic ketoacidosis, lactic acidosis).

High bicarbonate: Suggests metabolic alkalosis (e.g., prolonged vomiting, diuretic use, excess antacids).

Clinical Use:

Provides insight into acid–base status.

Helps differentiate metabolic vs. respiratory causes of abnormal blood pH.

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