Final answer:
In Chronic Obstructive Pulmonary Disease (COPD), the expiratory flow rate is impaired. This condition is diagnosed using spirometry, which shows a reduced FEV1/FVC ratio due to airway obstruction, distinguishing obstructive from restrictive lung diseases.
Step-by-step explanation:
In Chronic Obstructive Pulmonary Disease (COPD), patients experience impaired expiratory flow rates. This impairment can be diagnosed using spirometry, a method that measures the volume and speed of air that can be inhaled and exhaled. Spirometry results in COPD show a reduced ratio of FEV1 (forced expiratory volume in one second) to FVC (forced vital capacity), indicating difficulty in expelling air due to obstructed airways. In restrictive lung disease, by contrast, the FEV1/FVC ratio is typically within the normal range because the main problem is reduced lung volume, not airway obstruction.
Furthermore, COPD is characterized by an increase in the airway resistance, leading to air trapping and a reduced expiratory flow rate. The disease leads to progressively worsening symptoms over time, such as shortness of breath and difficulty performing physical activities like climbing stairs. This reduced ability to expel air from the lungs distinguishes obstructive lung conditions like COPD from restrictive lung diseases where the problem lies primarily in the stiffness or reduced compliance of the lung tissue.