Question: why is fev1 fvc reduced in asthma?
Answer: Obstruction of airflow is defined by a reduced FEV1 (forced exhalation volume in one second) to FVC (forced vital capacity). This is a result in a relatively greater decrease in FEV1 compared to FVC, whereas in restrictive disease these 2 parameters decrease proportionally and the FEV1/FVC ratio does not change.