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Carboxyhemoglobin (COHb)

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Carboxyhemoglobin (COHb)

Carboxyhemoglobin (COHb) is the term used to describe hemoglobin (the protein in red blood cells that normally carries oxygen from the lungs to the rest of the body) that has bonded with carbon monoxide instead of oxygen.

Carbon monoxide's bond with hemoglobin is much stronger than oxygen's bond with hemoglobin. When hemoglobin binds with carbon monoxide instead of oxygen, the blood can no longer carry enough oxygen.

Current as of: May 1, 2026

Author: WebMD Ignite Staff

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This information does not replace the advice of a doctor. WebMD Ignite, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

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