This is the amount of air that you can forcibly blow out in one second, measured in litres. Along with FVC it is considered one of the primary indicators of lung function.It is decreased in obstructive lung disease in proportion to severity of obstruction. It is even<unk>  in severe restrictive disease of lung.
Reduced FEV1
Confusion chest x ray
Pleural friction rub
Bronchial hyperresponsiveness
Paroxysmal nocturnal dyspnea
Increased bowel sounds
White out of the hemithorax
FEV1/FVC ratio