The rewards of quitting 20 minutes: heart rate, blood pressure drop 12 hours: carbon monoxide in blood stream drops to normal 2 weeks–3 months: circulation, lung function improve; heart attack risk begins to drop 1–9 months: cough less, breathe easier 1 year: risk of coronary heart disease cut in half 2–5 years: risk of cancer of mouth, throat, esophagus, bladder cut in half; stroke risk is reduced to that of a nonsmoker 10 years: half as likely to die from lung cancer; risk of kidney or pancreatic cancer decreases 15 years: risk of coronary heart disease same as nonsmoker's risk what is a benefit of quitting tobacco products? after 12 hours, lung function begins to improve. after 10 years, the risk of dying from lung cancer is cut in half. after five years, the risk of having a stroke is cut by 25%. over time, life expectancy is increased by 15 years.