Fluency, also known as stuttering, can begin
during childhood and, in some cases, last throughout life. Most people produce brief
disfluencies from time to time. For instance, some words are repeated
and others are preceded by "um" or "uh." Disfluencies are not
necessarily a problem; however, they can impede communication when a
person produces too many of them.
A fluency disorder can be characterized by the following disfluencies: