Table 2.
Classification of Asthma Severity: Method of Expert Panel Report 225
| Severity | Symptoms | Nighttime Symptoms | Lung Function |
| Severe persistent | Continual symptoms Limited physical activity Frequent exacerbations |
Frequent | FEV1/PEF ≤60% PEF variability >30% |
| Moderate persistent | Daily symptoms Daily use of short-acting beta-agonist Exacerbations affect activity Exacerbations ≥2/week |
>1/week | FEV1/PEF >60% but <80% PEF variability >30% |
| Mild persistent | Symptoms >2/week but <1/day Exacerbations may affect activity |
>2/month | FEV1/PEF ≥80% PEF variability 20% to 30% |
| Mild intermittent | Symptoms ≤2/week Asymptomatic between exacerbations Exacerbations brief |
≤2/month | FEV1/PEF ≥80% PEF variability <20% |
FEV1 : forced expiratory volume in one second; PEF: peak expiratory flow