Chronic obstructive pulmonary disease (COPD) is the result of complex interplay between clinical and molecular (ie, genetic) risk factors . These interactions are the reason that two individuals may have identical clinical risk factors, but only one will develop COPD. Identifying risk factors for COPD and better understanding their interactions may lead to strategies that reduce the prevalence of COPD.
Risk factors for COPD and strategies for risk reduction are discussed in this topic review. The clinical manifestations, diagnosis, staging, natural history, and treatment of COPD are reviewed separately. (See "Chronic obstructive pulmonary disease: Definition, clinical manifestations, diagnosis, and staging" and "Chronic obstructive pulmonary disease: Prognostic factors and comorbid conditions" and "Management of stable chronic obstructive pulmonary disease".)
Lung function normally increases as the lungs grow during childhood and adolescence, peaks shortly after 20 years of age, and then begins to decline gradually (figure 1). Risk factors for chronic obstructive pulmonary disease (COPD) cause one or more abnormal patterns of lung function as shown in the figure (figure 1):
- Reduced lung growth
- Premature lung function decline
- Accelerated lung function decline
Accelerated lung function decline is most common. However, each of these abnormal patterns can reduce lung function to an extent that the individual is considered to have COPD. (See "Chronic obstructive pulmonary disease: Definition, clinical manifestations, diagnosis, and staging".)