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electrolytes · HCO3 · CO2

Bicarbonate (CO2)

A measure of the blood's buffering capacity that reflects acid-base balance. Abnormal values point to breathing or metabolic processes shifting the body's acidity, and are read with the other electrolytes.

This page is general wellness education, not medical advice. Your own lab’s reference range and your clinician’s interpretation always take precedence.

Typical reference range

GroupGeneral range
Adults23 – 29 mEq/L

Units: mEq/L. Ranges vary by lab and assay — read yours against the range printed on your own report.

What high Bicarbonate (CO2) can mean

  • Vomiting
  • Certain lung conditions
  • Some diuretics
  • Metabolic alkalosis

What low Bicarbonate (CO2) can mean

  • Metabolic acidosis
  • Kidney disease
  • Severe diarrhea
  • Uncontrolled diabetes

Related markers

Sources