Final answer:
The term COPD is used when symptoms such as shortness of breath and cough with phlegm are present and spirometry confirms an obstructive defect with a reduced FEV1/FVC ratio.
Step-by-step explanation:
The term Chronic Obstructive Pulmonary Disease (COPD) can be used when symptoms of chronic bronchitis or emphysema are present and spirometry documents an obstructive defect. Spirometry is a diagnostic tool that measures the rate at which air can be expelled from the lungs, helping to diagnose obstructive diseases like COPD. An obstructive defect is indicated by a reduced ratio of FEV1 (Forced Expiratory Volume in one second) to FVC (Forced Vital Capacity), signaling reduced airflow and difficulty in exhalation. COPD is characterized by poor airflow as a result of a breakdown of connective tissues in the lungs, reduction in the number and elasticity of alveoli, and subsequently air becomes trapped in the lungs, leading to difficulties such as shortness of breath and a cough that produces phlegm.