Final answer:
COPD is a lung disease characterized by chronic poor airflow, involving two main conditions: chronic bronchitis and emphysema, commonly caused by tobacco smoking.
Step-by-step explanation:
Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized as a combination of primarily two conditions: chronic bronchitis and emphysema. Individuals with COPD experience chronic poor airflow, leading to symptoms such as shortness of breath and a productive cough. The disease is most commonly attributed to tobacco smoking and can result in significant reductions in the number and elasticity of alveoli, impairing the ability to fully exhale air from the lungs.
The physiological changes associated with COPD include the destruction of alveolar walls which decreases the lungs' surface area for gas exchange, and a loss of elastic fibers which leads to increased air trapping. Compromised gas exchange can result in lowered oxygen levels and an accumulation of carbon dioxide in the blood. While treatments such as supplemental oxygen and inhaled bronchodilators can alleviate symptoms, there is no cure for COPD, with the exception of lung transplantation in severe cases.