Diagnosis and staging of chronic obstructive pulmonary disease(COPD)#
| Severity | FEV1/FVC % | FEV1 % pred |
| 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 one second; FVC: forced vital capacity. All values are based on post-bronchodilator FEV1. #: recommended spirometry thresholds of Global Initiative for Chronic Obstructive Lung Disease 2003 5 and American Thoracic Society/European Respiratory Society COPD guidelines 2004 6; ¶: patients who smoke or have exposure to pollutants, have cough, sputum or dyspnoea, or have a family history of respiratory disease.