4.2 : 慢性阻塞性肺病 II：病理生理学

Chronic obstructive pulmonary disease, or COPD , is primarily caused by chronic airway inflammation due to exposure to irritants such as cigarette smoke, dust, or air pollution.

Inflammatory cells, including lymphocytes, macrophages, and neutrophils, invade the airway wall, releasing harmful mediators like leukotrienes  and cytokines.

Inhaled particles and oxidants produced by these inflammatory cells aggravate the inflammation.

Oxidants inhibit antiproteases compounds that protect against the breakdown of lung tissue.

Simultaneously, they increase the activity of proteases enzymes that degrade lung tissue.

This imbalance disrupts the natural balance between proteases and antiproteases, leading to the deterioration of alveoli and loss of lung elasticity.

As a result, the airways narrow, obstructing airflow, which promotes excessive mucus production and causes fluid buildup in the lungs.

In COPD, chronic inflammation causes oxidative stress, releasing free radicals that damage lung tissue, leading to bullae formation and alveolar wall deterioration, impairing gas exchange.