Stuttering is a communication disorder in which the flow of speech is broken by repetitions (li-li-like this), prolongations (lllllike this), or abnormal stoppages (no sound) of sounds and syllables. There may also be unusual facial and body movements associated with the effort to speak. Stuttering is also referred to as stammering.

There are four factors most likely to contribute to the development of stuttering: genetics ( approximately 60% of those who stutter have a family member who does also); child development (children with other speech and language problems or developmental delays are more likely to stutter); neurophysiology ( recent research has shown that people who stutter process speech and language in different areas of the brain than those who do not stutter); and family dynamics ( high expectations and fast-paced lifestyles can contribute to stuttering).

Stuttering may occur when a combination of factors comes together and may have different causes in different people. It is probable that what causes stuttering differs from what makes it continue or get worse.

Over three million Americans stutter or approximately 1% of the population.

Stuttering affects four times as many males as females.

Some 20 percent of all children go through a stage of development during which they encounter disfluencies severe enough to be a concern to their parents. Approximately 5 percent of all children go through a period of stuttering that lasts six months or more. Three-quarters of those will recover by late childhood, leaving about 1% with a long-term problem. The best prevention tool is early intervention.

Children and adults who stutter are no more likely to have psychological or emotional problems than children and adults who do not. There is no reason to believe that emotional trauma causes stuttering.