Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Flow-volume curves created by increasing effort and by coughing.
Top, Expiratory flow-volume curve recorded during a series of expirations with increasing efforts, finally producing a maximal flow-volume envelope. Bottom, Expiratory flow-volume curve recorded during coughing (solid line), approximating the maximal flow-volume envelope (dashed line).
