Chronic Obstructive Pulmonary Disease
A progressive, largely irreversible airflow limitation from smoking-driven small-airway inflammation and alveolar destruction; because the damage is structural, treatment focuses on slowing decline, relieving symptoms and preventing exacerbations.
First principles
COPD is airflow obstruction from two structural injuries, not reversible spasm
Chronic inhaled irritants (overwhelmingly cigarette smoke) drive persistent airway inflammation with two consequences. First, the small airways become inflamed, scarred and narrowed (chronic bronchitis component). Second, protease-antiprotease imbalance destroys alveolar walls (emphysema), losing the elastic recoil that normally holds airways open. Both narrow the airways in a way that is fixed, which is the defining difference from asthma: the obstruction is largely irreversible because it is structural damage, not smooth-muscle constriction that a bronchodilator can fully relieve.
Educational content pending clinical review. Not medical advice.