Explain the pathophysiology of COPD give clinical example of symptoms and pathophysiology associated with COPD.

COPD (Chronic Obstructive Pulmonary Disease) is a progressive and largely irreversible respiratory disorder caused by persistent airway inflammation. The primary causes of COPD are smoking, air pollution, and occupational exposures to chemical irritants or dusts. Pathophysiology includes mucus production in the bronchioles leading to thickening of their walls, increased collagen deposition in the alveolar spaces resulting in fewer functional alveoli available for gas exchange, decreased elastic recoil within the lung tissue due to loss of bronchial muscle tone and fibrosis (scarring) around small airways as well as large ones.

Clinically this results in cough, chronic sputum production, dyspnea (shortness of breath), fatigue and changes on physical examination like prolonged expiration time, prolonged expiratory phase with wheezing sounds heard during inspiration as well as expiration when patient breathe more forcefully.

Other symptoms can include chest tightness or pain with exercise or activity increases; along with accentuated inspiratory effort resulting from increased work required by ventilation. There may be widespread systemic effects due to systemic hypoxia such as headache, dizziness and confusion.