Stuttering is a speech disorder. People who stutter may repeat sounds, syllables, or words, or they may prolong sounds. There may also be interruptions to the normal flow of speech, known as blocks, along with unusual expressions or movements.
Stuttering affects more than 70 million people worldwide, including more than 3 million people in the United States. It is more common among men than women. Some people refer to stuttering as stammering or childhood onset fluency disorder.
Approximately 5–10% of all children will stutter at some point in their lives, but most will typically outgrow this within a few months or years. Early intervention can help children overcome stuttering.