COPD is also known as CORD, COAD, COLD, and many other acronyms, these three are short for chronic obstructive respiratory, airways, or lung disease. CAL refers to the same disease, and stands for chronic airway limitation.
Conditions grouped here are:
COPD is characterised by an increased residual volume (the amount of air left in the lungs after a full breath out), but other lung volumes are usually decreased.The FEV1/FVC ratio is decreased with COPD, meaning a person can't force out much air from their lungs in one second. (Normally someone can expire about 80% of their vital capacity in one second, this is reduced in COPD.)
(Formerly or formally? only: chronic bronchitis, emphysema and small airways disease)