Degree of severity	Symptoms and signs	Initial PEF (or FEV1)	Clinical course
Mild	Dyspnea only with activity (assess tachypnea in young children)	PEF ≥ 70 percent of predicted or personal best	Usually treated at home
			Prompt relief with inhaled short-acting beta2 agonist
			Possible short course of oral systemic corticosteroids
Moderate	Dyspnea interferes with or limits usual activity	PEF 40 to 69 percent of predicted or personal best	Usually requires office or emergency department visit
			Relief from frequent inhaled short-acting beta2 agonist
			Oral systemic corticosteroids; some symptoms last for one to two days after treatment begins
Severe	Dyspnea at rest; interferes with conversation	PEF < 40 percent of predicted or personal best	Usually requires emergency department visit and likely hospitalization
			Partial relief from frequent inhaled short-acting beta2 agonist
			Oral systemic corticosteroids; some symptoms last for more than three days after treatment begins
			Adjunctive therapies are helpful
Subset: life threatening	Too dyspneic to speak; perspiration	PEF < 25 percent of predicted or personal best	Requires emergency department visit/hospitalization; possible intensive care unit
			Minimal or no relief from frequent inhaled short-acting beta2 agonist
			Intravenous corticosteroids
			Adjunctive therapies are helpful