Table 1.

Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for classification of COPD1

GOLD stage	Descriptor	Signs and symptoms	Spirometry results based on post-bronchodilator FEV1
I	Mild	Mildly reduced airflow; sometimes a chronic cough and sputum production	FEV1/FVC < 70 FEV1 ≥ 80% predicted
II	Moderate	Worsening airflow; shortness of breath typically brought on by exertion	FEV1/FVC < 70 50% ≤ FEV1 < 80% predicted
III	Severe	Further worsening airflow; greater shortness of breath; reduced quality of life	FEV1/FVC < 70 30% ≤ FEV1 < 50% predicted
IV	Very severe	Severe reduction of airflow; chronic respiratory failure; greatly reduced quality of life	FEV1/FVC < 70 FEV1 < 30% predicted or FEV1 < 50% predicted plus chronic respiratory failure

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.