Step 1: Asthma severity is graded by daytime symptom frequency, night awakenings, rescue inhaler use, activity limitation, and lung function.
Step 2: Daytime symptoms throughout the day with daily (nightly) awakenings represent the most frequent pattern, which corresponds to severe persistent asthma.
Step 3: In severe asthma the short-acting beta-2 agonist is needed several times a day, there is extreme limitation of normal activity, and FEV1 is below 60 percent of predicted with a reduced FEV1/FVC ratio.
Step 4: The milder grades are excluded: mild intermittent has symptoms twice a week or less, mild persistent more than twice a week but not daily, and moderate has daily symptoms with weekly night awakenings, all less frequent than this patient.