Table 1.
GOLD stages of chronic obstructive pulmonary disease severity
| COPD severity |
Characteristics |
|
|---|---|---|
| FEV1/FVC | FEV1 | |
| GOLD Stage I (mild) | <70% | – |
| GOLD Stage II (moderate) | <70% | <50%–70% |
| GOLD Stage III (severe) | <70% | <30%–50% |
| GOLD Stage IV (very severe) | <70% | <30% or <30%–50% with respiratory insufficiency (defined as PaO2 < 60 mmHg and/or PCO2 < 50 mmHg while breathing air at sea level) |
Abbreviations: GOLD, global initiative for chronic obstructive lung disease; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 sec; FVC, forced vital capacity; PaO2, partial pressure of oxygen in arterial blood; PCO2, partial pressure of carbon dioxide.