Question

if someone can exhale forcefully for a short moment and then produces a weak stream of air with lots of wheezing the
4
multiple choice
fev1% will be high.
fvc will be below normal.
fef25 - 75 will be low.
fef25 - 75 will be high.

Explanation:

• FEV₁% (Forced Expiratory Volume in 1 second as a percentage of FVC): In obstructive lung diseases (which may present with wheezing), FEV₁% is low (e.g., in asthma, COPD). So the option “FEV₁% will be high” is incorrect.
• FVC (Forced Vital Capacity): In pure obstructive patterns (like mild - moderate asthma attacks without significant airway remodeling leading to restrictive components), FVC can be normal or even increased (due to air trapping in some cases). So “FVC will be below normal” is not the best answer here.
• FEF₂₅ - 75 (Forced Expiratory Flow between 25 - 75% of FVC): This reflects flow in the medium - sized airways. In conditions with airway obstruction (which can cause wheezing), there is narrowing of airways. Narrowed airways lead to reduced flow rates. So FEF₂₅ - 75 will be low. “FEF₂₅ - 75 will be high” is incorrect.

Answer:

FEF₂₅ - 75 will be low.