Spirometric classification of chronic obstructive pulmonary disease (COPD)
| Severity of obstruction | Post-bronchodilator FEV1/FVC | FEV1 % predicted |
| At risk | >0.7 | ≥80 |
| Mild COPD | ≤0.7 | ≥80 |
| Moderate COPD | ≤0.7 | 50–80 |
| Severe COPD | ≤0.7 | 30–50 |
| Very severe COPD | ≤0.7 | <30 |
FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. At risk are patients who: smoke or have exposure to pollutants; have cough, sputum or dyspnoea; and have a family history of chronic respiratory disease.