Chronic obstructive pulmonary disease (COPD), which is the third leading cause of death in the United States, affects millions of people around the world. COPD, which can include both emphysema and chronic bronchitis, affects the lungs making it very difficult to breathe. Cigarette smoking is the most common risk factor for developing COPD; however, only 15% to 20% of smokers develop COPD in their lifetimes. The onset of COPD also varies greatly from person to person; while some people do not develop respiratory symptoms until later in life, there are others who develop severe COPD at a very early age. Prior research has led to the discovery of the alpha-1 antitrypsin protein deficiency in association with COPD development. This discovery has generated further interest toward studying other genetic factors which may also affect an individual's likelihood of developing COPD. Therefore, the purpose of the Boston Early-Onset COPD study is to gain a better understanding of COPD risk factors in order to establish new possible methods of treatment for people affected by COPD.