Carbon Monoxide can cause great damage to humans and its affects can be found in many long-term smokers.

How does Carbon Monoxide affect the body?

Carbon Monoxide is breathed into the lungs from polluted or smoky air or from inhaling tobacco smoke; it is absorbed into the blood from the lungs. Carbon monoxide binds to haemoglobin in red blood cells about 200 times as readily as Oxygen, and it then deprives the body of Oxygen.

Health Problems Caused by Carbon Monoxide

Smokers can have between 2%-20% of their normal blood Oxygen taken up by Carbon Monoxide. To compensate for the shortage of Oxygen the body has to work harder with less fuel.
Carbon Monoxide damages health because:

• The smoker's heart beats faster trying to get enough oxygen to the body
• The heart itself gets less oxygen and this increases the risk of damage to the heart muscles and sudden death
• The smoker gets more breathless as the body has little spare Oxygen for any extra demands made by any exercise
• The linings of the arteries are more permeable to cholesterol and this causes a fatty build up increasing the risk of circulation problems, heart attack and stroke
• The supply of Oxygen needed for the healthy growth of a baby is reduced if a pregnant woman smokes
• The lack of Oxygen can affect the ability to concentrate and can cause tiredness
• Carbon Monoxide causes the blood to thicken 

When you stop smoking, the level of Carbon Monoxide in your blood falls almost immediately. It will be the same as a non-smoker's within a couple of days; your blood will carry more Oxygen. You'll have more energy, better circulation and increased concentration.