The Global Initiative for Obstructive Lung Disease (GOLD) criteria for COPD classify the severity of the disease based on spirometric measurements and symptoms.
Spirometry results are based on two measurements-
1. Forced vital capacity (FVC): This is the largest amount of air you can breathe out after breathing in as deeply as you can.
2. Forced expiratory volume (FEV-1): FEV-1 shows how much air you can exhale from your lungs in 1 second.
|
Stage |
Severity |
FEV1/FVC |
FEV1 (% predicted) |
|
GOLD 1 |
Mild |
< 0.70 |
≥ 80 % |
|
GOLD 2 |
Moderate |
< 0.70 |
50-79 % (≥ 50 %) |
|
GOLD 3 |
Severe |
< 0.70 |
30-49 % (≥ 30 %) |
|
GOLD 4 |
Very severe |
< 0.70 |
< 30 % |
The FEV1/FVC ratio being less than 0.70 confirms the presence of airflow limitation that is not fully reversible, which is a hallmark of COPD.