Not troubled by breathlessness except with strenuous exercise.
Troubled by shortness of breath when hurrying on the level or walking up a slight hill.
Walks slower than people of the same age on the level because of breathlessness or has to stop for breath when walking at own pace on the level.
Stops for breath after walking about 100 m or after a few minutes on the level.
Too breathless to leave the house or breathless when dressing or undressing.