CO₂
The blood's buffering capacity — a marker of acid-base balance.
What is it
Total carbon dioxide reflects bicarbonate levels in blood and indicates buffering capacity for acid-base balance.
Why it's measured
CO₂ has been used in evaluating acid-base status and respiratory function in clinical research.
Reference range
Standard laboratory reference
23 – 29 mEq/L
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
Where does your number land?
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Drag to your own Carbon Dioxide (CO₂) result.
Educational only, not a diagnosis. Ranges vary by laboratory. See which panel includes Carbon Dioxide (CO₂).
What results may indicate
Elevated
Has been associated with respiratory and metabolic alkalosis in research literature.
Lower
Has been associated with metabolic acidosis in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of standard electrolyte panels.
Related markers
Common questions
Total carbon dioxide reflects bicarbonate levels in blood and indicates buffering capacity for acid-base balance.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Carbon Dioxide (CO\u2082) is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Carbon Dioxide (CO\u2082) is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Find the right panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.
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