Asthma classification*	Symptom frequency	Lung function†	Medications required to maintain long-term control
Mild intermittent	Daytime: 2 days per week or less	PEF or FEV₁: 80 percent or more of predicted function	No daily medication needed
Mild intermittent	Nighttime: 2 nights per month or less	PEF or FEV₁: 80 percent or more of predicted function	No daily medication needed
Mild persistent	Daytime: more than 2 days per week, but less than 1 time per day	PEF or FEV₁: 80 percent or more of predicted function	Low-dosage inhaled corticosteroid delivered by nebulizer or metered-dose inhaler with holding chamber, with or without a face mask, or by dry-powder inhaler in children 5 years and younger
Mild persistent	Nighttime: more than 2 nights per month	PEF or FEV₁: 80 percent or more of predicted function
Moderate persistent	Daytime: daily	PEF or FEV₁: 60 to 80 percent of predicted function	Children 5 years and younger: low-dosage inhaled corticosteroid and long-acting beta₂ agonistor medium-dosage inhaled corticosteroid Children older than 5 years: low- to medium-dosage inhaled corticosteroid and long acting inhaled beta₂ agonist.
Moderate persistent	Nighttime: more than 1 night per week	PEF or FEV₁: 60 to 80 percent of predicted function
Severe persistent	Daytime: continual	PEF or FEV₁: 60 percent or less of predicted function	High-dosage inhaled corticosteroid and long-acting beta₂ agonist
Severe persistent	Nighttime: frequent	PEF or FEV₁: 60 percent or less of predicted function