(Stammering; Disfluent Speech)


Stuttering is a speech disorder. It causes a person to repeat sounds, syllables, or words. Some sounds may be long and speech may be interrupted.


The exact cause is not known. It may happen when:

  • A child's ability to speak does not match his verbal demands
  • Certain genes
  • A person has a stroke, head trauma, or other type of brain injury
  • A person has emotional trauma (rare)

Muscles and Nerves Involved in Speech

Tongue Innervation
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Risk Factors

Stuttering is more common in males and in children who are 2 to 6 years of age. Family history also raises the chances of stuttering.


Problems may be:

  • Repeating sounds, syllables, or words
  • Making long sounds within words
  • Between-word pauses and lack of sound
  • Spurting speech


The doctor will ask about your symptoms and health history. A physical exam will be done. A speech language therapist may also do an exam. This is often enough to make the diagnosis.


There is no cure. The goal of treatment is to manage symptoms. This can with therapy to:

  • Improve the ability to speak smoothly
  • Learn ways to lessen stuttering, such as speaking more slowly or using breathing methods


There are no current guidelines to prevent stuttering.


American Speech-Language-Hearing Association
The Stuttering Foundation


Canadian Stuttering Association
University of Alberta—Institute for Stuttering Treatment and Research


Cruz C, Amorim H, Beca G, Nunes R. Neurogenic stuttering: a review of the literature. Rev Neurol. 2018;66(2):59-64.
Stuttering. American Speech-Language-Hearing Association website. Available at:
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Accessed April 9, 2020.
Stuttering. National Institute on Deafness and Other Communication Disorders website. Available at:
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Updated March 6, 2017. Accessed April 9, 2020.
Last reviewed February 2020 by EBSCO Medical Review Board Rimas Lukas, MD

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