0

None except during strenuous exercise

1

Occurring when hurrying on level ground or walking up a slight incline

2

Resulting in walking more slowly than people of the same age on level ground

or

Resulting in stopping for breath when walking at own pace on level ground

3

Resulting in stopping for breath after walking about 100 meters or after a few minutes on level ground

4

Preventing the person from leaving the house

or

Occurring when dressing or undressing