The American Cancer Society lists some of the immediate and long-term health benefits of quitting smoking:
After 20 minutes, blood pressure drops to normal.
After 8 hours, the carbon monoxide level in the blood drops to normal.
After 48 hours, nerve endings start regrowing and the senses of smell and taste are enchanced.
In one to nine months, coughing, sinus congestion, fatigue, and shortness of breath decrease and cilia (tiny, hair like cells that move continually to clean air that is breathed in) regrow in the lungs.
After five years, the chance of dying from lung cancer decreases by almost half.
After 15 years, the risk of heart disease is equal to that of a nonsmoker, and the risk of dying from lung cancer is only slightly higher than that of a non smoker.