Chronic obstructive pulmonary disease (COPD) is a lung disease that causes obstruction, resulting in breathing issues. The Global Initiative for Chronic Obstructive Lung Disease (GOLD)’s new definition no longer distinguishes between chronic bronchitis and emphysema. Before the new definition, chronic bronchitis and emphysema were airflow-limited states, which are subtypes of COPD.
Emphysema can be defined as a permanent and abnormal enlargement of air spaces along with the destruction of alveolar walls but without obvious fibrosis. The term “emphysema” can also be used for the abnormal presence of gas or air in the tissues. Most cases of COPD can be prevented by decreasing exposure to the risk factors.
1. Risk Factors
One of the main risk factors associated with COPD or emphysema is cigarette smoking. It is estimated about 15% to 20% of 1-pack smokers and 25% of 2-pack smokers develop COPD. This includes pipe smoking and secondhand and thirdhand smoke. Environmental exposures to smoke from occupational and home environments (fuel cooking and poor ventilation) are also considered risk factors. Various reviews have also recommended the need to improve air quality. Genetics is also another risk factor. The most well-studied genetic factor that may contribute to COPD is the alpha-1-antitrypsin (AAT) deficiency, an autosomal codominant condition.