COPD by severity according to the GOLD criteria.
| Stage | FEV1/FVC | FEV1 predicted % |
|---|---|---|
| Mild (GOLD I) | <0.7 | ≥80 |
| Moderate (GOLD II) | <0.7 | 50–80 |
| Severe (GOLD III) | <0.7 | 30–50 |
| Very severe (GOLD IV) | <0.7 | <30 |
FEV1 = forced expiratory volume in one second; FVC = forced vital manoeuvres; COPD = chronic obstructive pulmonary disease; GOLD = global initiative for chronic obstructive lung disease guidelines.