Other testsReported in mmol/LCarbon dioxide (bicarbonate)
Mostly bicarbonate, the blood’s main alkaline buffer. It shows whether acid is building up or being lost.
What it measures
The “CO2” on a chemistry panel is not the gas you exhale, measured directly. It is almost entirely bicarbonate dissolved in the serum. Bicarbonate buffers acid. Lungs and kidneys keep it in range: lungs by blowing off carbon dioxide gas, kidneys by reclaiming or dumping bicarbonate. The adult interval on this panel is 21–31 mmol/L.
Why it is on the panel
It completes sodium and chloride. Those three numbers are how a basic panel describes acid–base balance without a blood gas. Diarrhea, kidney disease, lung disease, and some medicines leave recognizable fingerprints here.
How to read it
Read carbon dioxide with chloride and sodium. Low bicarbonate plus high chloride is the pattern of metabolic acidosis, including diarrhea and some kidney problems. High bicarbonate plus low chloride fits metabolic alkalosis, including vomiting and diuretic use. A high bicarbonate can also be the kidney’s compensation for chronic lung disease.
When it runs higher
Vomiting, diuretics, and volume depletion raise bicarbonate. Chronic lung disease raises it as compensation when the lungs cannot clear carbon dioxide gas well. A mildly high result in someone on a water pill is a familiar pattern.
When it runs lower
Diarrhea loses bicarbonate directly. Kidney disease, diabetic ketoacidosis, and lactic acidosis consume it as they generate acid. A low result with a high glucose is a combination that needs prompt medical advice. Deep, rapid breathing can be the body’s attempt to compensate.
Same group
Other Other tests
How to use this page
This page explains what the measurement is for. It is educational. Your Healiam report includes the reference interval for your age and sex, and a clinician reads that result with your history, medicines, and the rest of the panel. Talk with a clinician before changing diet, supplements, or treatment because of a number on a report.
Carbon dioxide
Carbon dioxide is part of the full panel.
No referral or insurance required.
One preventive draw covers this measurement and the rest of the Healiam panel. CLIA-certified results come back in days.