What is the reference range for Carbon Dioxide (Total CO₂/Bicarbonate)?

The standard reference range for Carbon Dioxide (Total CO₂/Bicarbonate) is 22–29 mmol/L (laboratory-specific).. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Which tests measure Carbon Dioxide (Total CO₂/Bicarbonate)?

Carbon Dioxide (Total CO₂/Bicarbonate) is measured in 1 test on BiomarkersLabs.com, including Comprehensive Metabolic Panel, Plasma.

Biomarker Reference · CO₂

What does the Carbon Dioxide (Total CO₂/Bicarbonate) test measure?

Carbon Dioxide (Total CO₂/Bicarbonate) (CO₂) is a clinical biomarker used in metabolic-diabetes assessment. The total CO₂ measurement on a metabolic panel is predominantly bicarbonate (HCO₃⁻), with a small contribution from dissolved CO₂ and carbonic acid. It is measured in 1 laboratory test on BiomarkersLabs.com.

Reference Range: 22–29 mmol/L (laboratory-specific).
Units: mmol/L, mEq/L
Measured In: 1 test
Category: Metabolic

Functional medicine optimal24–28 mmol/L; extremes warrant blood gas analysis to clarify the primary disorder.

What is Carbon Dioxide (Total CO₂/Bicarbonate)?

The total CO₂ measurement on a metabolic panel is predominantly bicarbonate (HCO₃⁻), with a small contribution from dissolved CO₂ and carbonic acid. Bicarbonate is the body's main buffering anion, regulated by renal reabsorption and regeneration in response to acid–base disturbances, and by respiratory control of PCO₂.

Why is Carbon Dioxide (Total CO₂/Bicarbonate) measured?

Low CO₂ (<22 mmol/L) indicates metabolic acidosis or respiratory alkalosis with renal compensation; high CO₂ (>29 mmol/L) reflects metabolic alkalosis or compensated respiratory acidosis. Interpreting CO₂ requires integration with the anion gap, chloride, and clinical context—or ideally arterial or venous blood gases for a complete acid–base picture.

Reference ranges

Standard reference: 22–29 mmol/L (laboratory-specific).
Functional medicine optimal: 24–28 mmol/L; extremes warrant blood gas analysis to clarify the primary disorder.
Units: mmol/L, mEq/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.

Tests that measure Carbon Dioxide (Total CO₂/Bicarbonate)

1 test on BiomarkersLabs.com include this biomarker.

BML-MET-025Comprehensive

Comprehensive Metabolic Panel, Plasma

Carbon Dioxide (Total CO₂/Bicarbonate) reference range in this test: 22–29 mmol/L (laboratory-specific).

Related clinical conditions

Related Biomarkers

Frequently measured alongside

GlucoseGluc6 tests Blood Urea NitrogenBUN5 tests Serum CreatinineCr6 tests Estimated Glomerular Filtration RateeGFR6 tests SodiumNa6 tests PotassiumK6 tests ChlorideCl6 tests Calcium (Total)Ca4 tests

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