After 20 minutes blood pressure and pulse rate decreased and hand and foot temperature increased. After 8 hours Carbon monoxide levels in the blood drop to normal and blood oxygen levels rise to normal. After 24 hours, the risk of heart attack is reduced. After 48 hours Nerve endings begin to regenerate and the ability to smell and taste increases 2 weeks to 3 months Circulatory system improves, walking becomes easier, no more frequent coughing or wheezing, and lung function improves significantly in just a few months. 1-9 months Further improvement in lung function leads to less fatigue and shortness of breath, and cilia return to normal function. After 1 year The risk of coronary heart disease and heart attack is reduced to half that of smokers. After 5 years, the risk of stroke is reduced to the same level as in non-smokers. After 10 years, the risk of lung cancer decreases. However, even after 10 years of quitting smoking, the risk of lung cancer was still higher than in people who had never smoked. 15 years The risk of coronary heart disease and heart attack is similar to that of never smokers, and the risk of death is similar to that of nonsmokers. The cost savings of quitting smoking for 15 years is about 150,000 RMB.