Stuttering is when speech does not flow smoothly. Speech is interrupted by “blocks” (no sound comes out at all), repeating initial sounds (ex: b-b-b-ball), prolongations (ex: pummmmmmkin), and/or repeating words and/or phrases (ex: my-my-my, my mom-my mom-my mom). Some repetitions can be developmental until a certain age. Fluency disorders can have a large impact on an individual’s self esteem and ability to communicate in different environments.

Severe stutterers can display secondary characteristics such as tight eye blinking, head nodding, pursing of the lips, movement of hands or feet, etc. Secondary's are a visual “struggle” to get a word out.