Carbon Dioxide · high result
What does a high Carbon Dioxide mean?
Short answer
Serum CO2 on a metabolic panel is mostly bicarbonate. A high value means metabolic alkalosis or compensation for chronic lung disease: vomiting, diuretics, low potassium, excess antacids or baking soda, and COPD or sleep apnea raising CO2 retention. Mild elevations are common with diuretics and rarely matter; larger ones are read with potassium, chloride and the clinical picture.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
What is the normal range for Carbon Dioxide?
- age 18+: 22.0 – 29.0 mmol/L
Full reference table, citations and testing options: Carbon Dioxide biomarker page.
What are the common causes of high Carbon Dioxide?
- Thiazide or loop diuretics
- Vomiting or nasogastric losses, low potassium
- Chronic lung disease with CO2 retention, severe sleep apnea
- Excess antacid or bicarbonate intake
- Cushing's syndrome, hyperaldosteronism
What symptoms go with high Carbon Dioxide?
- Usually none
- Muscle cramps, twitching, lightheadedness when marked
What do clinicians usually check next?
- Potassium, chloride, sodium (the anion gap), kidney function
- Medication review
- Blood gases and lung evaluation if lung disease is suspected
How do you recheck Carbon Dioxide?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Basic Metabolic Panel | Test · 8 biomarkers | $20.99 | Yes | 1–3 business days |
Common questions
Is a CO2 of 31 a concern?
Rarely — it is a common finding on diuretics or after vomiting. Persistent values above ~32 with low potassium warrant a look at the cause.
Sources
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.