in the vast majority of people smoking is the cause of emphysema. exactly how smoking destroys the air sac linings in the lungs isn't known. however studies show that smokers are about six times more likely to develop emphysema than nonsmokers. estimates vary but more than 10 million people in the u. s. likely have emphysema or another form of chronic obstructive pulmonary disease. emphysema and chronic bronchitis are the fourth-leading cause of death in the country. interestingly most heavy smokers do not develop emphysema. why some smokers get emphysema and others do not is unknown. all heavy smokers experience other negative health effects of smoking though.
what causes emphysema?