How does COPD affect breathing

How does COPD affect breathing, copd treatments, how is copd diagnosed, what causes copd, what are the 4 stages of copd, is copd contagious, what is copd, copd pathophysiology, types of copd, Chronic obstructive pulmonary disease (COPD),

How does COPD affect breathing,
copd treatments,
how is copd diagnosed,
what causes copd,
what are the 4 stages of copd,
is copd contagious,
what is copd,
copd pathophysiology,
types of copd,
Chronic obstructive pulmonary disease (COPD),