What Happens when you quit?
Within 12 hours after you have your last cigarette, your body will begin to heal itself. The levels of carbon monoxide and nicotine in your system will decline rapidly, and your heart and lungs will begin to repair the damage caused by cigarette smoke. Within a few days, you'll probably begin to notice some remarkable changes in your body. Your sense of smell and taste may improve. You'll breathe easier, and your smoker's hack will begin to disappear, although you may notice that you still cough for a while. And you'll be free from the mess, smell, inconvenience, and expense of cigarette smoking.
Nicotine and carbon monoxide leave the body in the first few hours after stopping smoking, although it may take up to two days for nicotine by-products to leave the body. Within a month of cessation, blood pressure returns to the normal level, and lung function has improved. After around three months, the lungs may have regained the capacity to clean themselves properly, depending on whether irreparable lung damage has occurred, and blood flow to the limbs will have improved. (1)
Day1
Within a few hours of quitting, all traces of carbon monoxide have left your body.
Day2
All cigarette by-products have left your system and your sense of taste and smell improve.
2 to 3 weeks
Most withdrawal symptoms have gone.
3 weeks
The hair-like cilia lining in your lungs starts to sweep out the build-up of tar and mucus, enabling you to cough it up.
4 weeks
Exercising is easier because more air is getting into your lungs, the climb up the stairs should be easier.
2 months
The blood flow to your hands and feet improves, keeping them warmer.
1 year
Your risk of heart disease is almost half that of someone who is still smoking.
10 to 15 years
After 10 to 15 years, a previous tobacco user's risk of premature death approaches that of a person who has never smoked. About 10 years after quitting, an ex-smoker's risk of dying from lung cancer is 30 percent to 50 percent less than the risk for those who continue to smoke (2).
Sources:
1. U.S. Department of Health and Human Services Public Health Service National Institutes of Health. US Department of Health, Education and Welfare. Smoking and Health, 1979.
2. Source: US Department of Health & Human Services, 1990.