Chronic obstructive pulmonary disease is an umbrella term for progressive lung diseases, primarily chronic bronchitis and emphysema — conditions that make breathing increasingly difficult. Most COPD sufferers have bronchitis and emphysema simultaneously.
The disease occurs primarily in current or former smokers over the age of 40. Long-term exposure to secondhand smoke or other pollutants in the air may also trigger COPD, and there is a genetic condition called AAT (alpha-1 antitrypsin) deficiency that can trigger the disease even in those without other risk factors.
COPD is distinct from asthma, though there is overlap between the two diseases, and researchers have begun to reevaluate the concept of asthma and COPD as separate conditions.
It has also been found that children who suffer from asthma are at possible increased risk of developing COPD in early adulthood.