---
title: What is %COHb?
description: What is %COHb?
---

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# What is %COHb?

## What is %COHb?

%COHb is the percentage of red blood cells carrying CO instead of oxygen in the blood. When you inhale smoke from a cigarette, CO is absorbed into your blood through the lungs, Oxygen (O2) is carried around the body by red blood cells. CO binds with haemoglobin in the red blood cells to form carboxyhaemoglobin, otherwise known as ‘blood CO’ or %COHb preventing red blood cells from carrying oxygen(2). CO binds with haemoglobin 200 times more readily than oxygen and a very heavy smoker may have 10% of their blood cells taken up by CO, depriving the body of oxygen.

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**References**

2\. Blumenthal I. Carbon monoxide poisoning \[Internet\]. PubMed Central (PMC). 2017 \[cited 14 March 2017\]. Available from: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1281520/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1281520/)

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