[RS] Q.14 What is FEV1 ?

Ans.

FEV1 (Forced expiratory volume):

Definition : The volume of air expired forcefully at one second is called forced expiratory volume. It is also know as timed vital capacity.

Normal value: (In a normal person FEV1 is more than 80% in one second):

1.     FEV1 is – 80% of vital capacity in first second (FEV1 /FVC %).

2.     FEV1 is – 93% of vital capacity in 2 second.

3.     FEV1 is – 97% of vital capacity in 3 second.