Within 20 minutes:

Your blood pressure and pulse rate drop to normal. Body temperature of hands and feet increase to normal.

Within eight hours:

Carbon monoxide level in the blood drops to normal and oxygen levels in blood rise to normal. Smoker's breath disappears.

Within 24 hours:

Chance of a heart attack decreases.

Within 48 hours:

Nerve endings start regrowing. Ability to taste and smell enhances.

Within three days:

You'll breath easier.

Within two weeks to three months:

Circulation improves. Walking becomes easier. Lung function increases up to 30 per cent.

Within one to nine months:

You'll cough less. Sinus congestion and shortness of breath decrease. The cilia that sweep debris from your lungs will grow back. You'll feel more energetic.

Within one year:

Excess risk of coronary heart disease is half that of a smoker.

Within two years:

Your heart attack risk drops to near normal.

Within five years:

Lung cancer death rate for average former smoker decreases by almost half. Stroke risk is reduced to that of a non-smoker five to ten years after quitting. Risk of cancer of the mouth, throat, and esophagus, is half that of a smokers.

Within 10 years:

Lung cancer death rate is similar to that of a non-smoker's. Precancerous cells are replaced. Risk of cancer of the mouth, throat, esophagus, bladder, kidney, and pancreas decreases.

Within 15 years:

Your risk of coronary heart disease is that of a non-smoker's.