Carbon monoxide


Carbon monoxide is a poisonous gas that you can’t see, smell or taste.

Tobacco contains carbon and when it burns it gives off carbon monoxide. When you smoke a cigarette and inhale the smoke, you breathe in carbon monoxide which is then absorbed through the lungs into the blood stream.

What does it do to my body?

Red blood cells transport oxygen around your body, but when you smoke, carbon monoxide takes some of the oxygen’s place. When blood cells carry carbon monoxide they can’t carry oxygen. The red blood cells carrying the carbon monoxide are more sticky than normal and the walls of the arteries that carry blood away from the heart around the body are more likely to develop fatty plaques inside them so that blood can’t flow through so easily. The result is that the heart is starved of oxygen and can’t work as well as it should. With less oxygen being carried in each cell smokers get out of breath more easily than non-smokers.


Because of carbon monoxide smokers are more at risk of heart attacks and stroke. The good news is that when you stop smoking your carbon monoxide levels drop very quickly. In 24 to 48 hours your carbon monoxide levels go back to the level of a non-smoker.

Carbon monoxide monitor

When you come to a stop smoking session for the first time we will measure your carbon monoxide level by asking you to do a breath test. This involves you holding your breath for 10 to 15 seconds and then blowing into a carbon monoxide hand held monitor. Most monitors use a simple traffic light system to show you how much carbon monoxide is in your body. The majority of smokers will get a red light in their first session. The level of carbon monoxide recorded will depend on how many cigarettes you smoke, how deeply you inhale and how long it has been since your last cigarette.

Just 24-48 hours after your last cigarette you will get a green non-smoker reading. Carbon monoxide is the first toxin or by product to be eliminated from your body when you quit. This is why each time you come to a session we ask you to blow into the monitor so you can see for yourself that you are a non-smoker.

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Call 0800 612 0011 (free from a landline) or 0330 660 1166 Monday to Friday between 8.30am and 4.30pm and Saturdays between 9am until 4.30pm


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