Detail (Long)
<b>Severity of airflow obstruction</b> (GOLD 1/mild: FEV<sub>1</sub> ≥80% predicted; GOLD 2/mod: FEV<sub>1</sub> 50% to <80% predicted; GOLD 3/severe: FEV<sub>1</sub> 30% to <50% predicted; GOLD 4/very severe: FEV<sub>1</sub> <30% predicted).