Within minutes of quitting, your heart rate and blood pressure drop. Within 12 hours, the carbon monoxide level in your blood returns to normal. These rapid changes significantly reduce your risk of heart attack and improve your overall cardiovascular health almost instantly.

In the short term, your circulation improves and your lung function increases. You'll likely notice that breathing becomes easier, and you'll experience less coughing and wheezing. Your senses of smell and taste will also start to recover, making food more enjoyable and improving your perception of everyday scents.

Quitting smoking dramatically reduces your risk of developing various cancers, including lung, throat, mouth, and esophageal cancers. After 10 years of being smoke-free, your risk of lung cancer is about half that of a continuing smoker, and your risk of cancers of the mouth, throat, esophagus, bladder, kidney, and pancreas decreases significantly.

Furthermore, stopping smoking greatly lowers your risk of heart disease, stroke, and chronic obstructive pulmonary disease (COPD). After 15 years, your risk of coronary heart disease is similar to that of a non-smoker. Quitting also improves your overall quality of life, increasing your life expectancy and giving you more years free from debilitating smoking-related illnesses.