Stuttering interrupts the flow of speech. It may involve the repetition, prolongation, or blockage of a word or part of a word that a person is trying to say. Other physical movements, reflective of tension or struggle with speaking, such as eye blinks, head turns, or facial grimacing may be present. Stuttering severity may vary considerably from one day to another and from one situation to another.

Therapy may include full assessment, indirect and/or direct treatment (depending on the age of the child), and teaching of strategies for disfluent speech ranging from mild to profound. Parent education and training is a crucial part of fluency therapy. The social-emotional impact of stuttering is addressed with older children and adults.