Question

How does hyperinflated breathing affect the forced expired volume (FVC) and forced expired volume in 1 second (FEV₁)?

Answer 1

FVC or force vital capacity is the volume of the air that can be expired rapidly with maximum force followed by a maximum inspiration. Force expiratory volume in 1 second is represented as FEV 1 . The volume expired in the first second of FVC is called FEV​​​​ 1. Hyperinflated breathing is a obstructive condition of the lungs, where the airways and respiratory passage is facing any kind of blokadge. In this condition the person has to put more effort for expulsion of air from the lungs. This condition is also known as obstructive lung disease. In this hyperinflated breathing condition, the FEV 1 is reduced than the normal because the lungs have low flow rates for high airway resistance. The reduction in FEV 1 is much greater than normal. FVC or forced vital capacity is also reduced due to obstruction in airways, because the person need more effort to expired rapidly with maximum force following a maximum inspiration. The hyperinflated lungs don't have enough strength to achieve normal FVC, so FVC is reduced but reduction of FVC is smaller. The FEV 1 /FVC ratio is also lower than normal (80%). This ratio is helpful for calculating FEV 1 % in different lungs disease. In this hyperinflated condition this % is reduced than normal conditions.

In this way hyperinflated breathing affect the FVC and FEV 1 in our body.