Quitting smoking reduces respiratory problems, reduces infertility risks and decreases the chances of certain diseases, according to the Centers for Disease Control and Prevention. The benefits increase the longer a person goes without smoking, but quitting at any age improves health and reduces the risk of early death.
Many physical effects of smoking improve in the days and weeks after a person stops smoking. Within 20 minutes of the last cigarette, the heart rate returns to a normal range, states the American Lung Association. Within 12 hours, carbon monoxide levels enter the normal range. Lung functioning improves and heart attack risks drop in the first three months after quitting. Coughing and shortness of breath often improve in one to nine months.
Smoking increases the risk of several medical conditions and diseases. When a person stops smoking, the risk of lung cancer, other cancers, heart disease and lung diseases such as chronic obstructive pulmonary disease, or COPD, decreases, says the CDC. Pregnant women decrease the risk of having babies with low birth weight when they quit smoking.
The chances of having certain health problems decrease the longer a person goes without smoking. After one year of not smoking, the risk of coronary heart disease drops to half that of someone who still smokes, notes the American Lung Association. By 15 years, a former smoker has the same risk of developing coronary heart disease as a nonsmoker.