1-American Thoracic society score (ATS):
Grade 0:- No breathlessness except with strenuous exercise.
Grade 1:- Breathlessness when hurrying on the level or walking up a slight hill.
Grade 2:- 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 level.
Grade 3:- stop for breath after walking about 100 yards (96 meter) or a few minutes on the level.
Grade 4:- Too breathless to heave the house or breathless when dressing or underdressing.
2-New york heart association score (NYHA)
1. Grade I (minimal Dyspnea): Dyspnea on running or on doing more than ordinary effort .
2. Grade II : on doing ordinary effort .
3. Grade III (considerable Dyspnea) : on doing less than ordinary effort .
4. Grade IV : Dyspnea at rest.