What Is Stuttering?

  • Catrin Emily Jones Bachelor of Science - BS, Psychiatric/Mental Health Nurse/Nursing, Swansea University
  • Celina-Ruth Centeno CarterMaster of Science - MS, Clinical Psychology, Swansea University, UK
  • Philip James Elliott B.Sc. (Hons), B.Ed. (Hons) (Cardiff University), PGCE (University of Strathclyde), CELTA (Cambridge University) , FSB, MMCA


Stuttering, also known as stammering or childhood-onset fluency disorder, is a communication disorder that disturbs a person’s fluency of speech. Stuttering is considered the most common type of speech disorder. But it remains a poorly understood condition, which results in sufferers being stigmatised, so it is important to understand stuttering to combat ignorance, increase awareness about the condition, and continue the discovery of things that will benefit people who stutter.1,2,3

What is stuttering?

Stuttering is a set of disturbances that disrupt the natural flow of speech. It is characterised by certain types of disfluencies that can interrupt the rhythm of speech and can be accompanied by negative reactions to speaking, avoidance and struggling behaviours, as well as physical tension.4 

About 1% of the world’s population is affected by stuttering.5 Generally, stuttering is more common in those assigned male at birth (AMAB) than those assigned female at birth (AFAB), with a ratio of over 4:1.6,7

Stuttering is a variable condition, which means that its features and severity differ from person to person and depend on numerous factors.8 If a case of stuttering is identified and treated early, it decreases the probability of it turning into a chronic condition.9

The most common characteristics of stuttering are:

  • Repetition of sounds, words, syllables, and phrases (e.g., “H-h-how are you?”)
  • Blocking (otherwise known as blocks or stoppages), where making sounds is attempted but nothing comes out
  • Prolonged sounds (e.g. “Hooooow are you?”)6

People who stutter may also have associated secondary complications involving non-verbal behaviours and motor movements. 

Examples include: 

  • grimacing 
  • tics 
  • eye blinks 
  • tremors 
  • head jerking 
  • breathing movements

People with a stutter may also deliberately try to avoid social situations or speaking specific words for fear they will feel embarrassed.6,10

Factors that influence stuttering

There has been a wide range of theories about the origins of stuttering, but its precise cause within the brain and nervous system has still not been clarified. Therefore, identifying stuttering can be difficult and the use of multifactorial research is necessary because it takes into consideration the impacts of multiple factors such as pathology, psychology, acoustics, and signal processing.11,1
Factors examined by research include:

Biological factors

Brain mapping studies have identified that people who stutter show differences in their brain anatomy and functioning compared to people who don’t.12,13 More precisely, people who stutter show reduced activity in their superior temporal gyrus - a temporal lobe area in the human brain that houses Wernicke’s area (an important region of the brain for understanding and generating speech).13 

These changes can contribute to neurodevelopmental disorders which affect speech-motor control. Stuttering also can be the result of psychological, cellular, physiological, and genetic disorders.12

Genetic factors

Stuttering is not generally considered a purely genetic disorder. But some studies have found instances of several cases of stuttering in the same family. So, the possibility of there being a hereditary component remains under consideration. 

In support of this, the National Health Service (NHS) maintains that approximately 2 in 3 individuals who stutter have a family history of stuttering. Research has also discovered it is more likely that a case of stuttering will persist over time if there is a history of stuttering in the family.2,14-16

Neurodevelopmental factors

There is increasing evidence that there are deficits in cognitive and metalinguistic skills in children who stutter. In existing studies, children who stutter have shown poorer executive function.17 

Executive function is a blanket term that relates to all the cognitive abilities we rely on in everyday life, including problem-solving, reasoning, emotional control, and working memory.18 It is thought that the deficits or the delay in the development of these skills might contribute to the start of stuttering in an individual.

Environmental factors

The environment, including other people within it, might affect a person who stutters negatively because speaking for them can become a traumatic experience. People who stutter – especially children – may speak less and conceal their problems with speech to avoid the risk of stigma and to feel safer. This can result in isolation and be confusing.19 Unfortunately avoiding speaking in this manner, can also make the stuttering worse.20

Parenting styles

It is also important to factor in the attitudes of the parents to stuttering as a possible contributory factor, especially as parents play a central role in the first recognition and identification of stuttering. 

Studies suggest that the way in which a parent responds to stuttering can affect how the person stuttering feels about their stutter, so parental negative attitudes can be damaging.21 A negative family attitude toward stuttering could lead to the person feeling anxious and frustrated when having to speak or even to them not speaking at all.22


The ability to speak more than one language increases a child’s probability of being diagnosed as stuttering, even if they do not stutter. 

In bilingual children especially, it can be hard to work out whether their dysfluencies are caused by stuttering or by knowing more than one language.23

Emotional factors

People who stutter often experience mental health issues such as increased anxiety (especially social anxiety), poor self-esteem, and negative feelings.24 

Stuttering can diminish a person’s confidence and bear an even larger impact on their quality of life if they begin to limit their participation in social and professional opportunities and activities.25 For children, one of the biggest obstacles arising from stuttering is low resilience, which can make it difficult for them to thrive in schooling and social situations.26

In Briley et al’s study of the link between stuttering and depression, they found that people who stutter reported higher levels of depressive symptoms than people who don’t. Also, there was a larger amount of suicidal ideation (thinking about suicide) in people AMAB who stutter compared to people AMAB who don’t, and the risk of this increasing with age. Therefore, speech and language therapists need to always maintain awareness and knowledge about this relationship between stuttering and depression.27

Types of stuttering

There are two main types of stuttering – developmental and neurogenic.

Developmental stuttering

Developmental stuttering begins in childhood, which is a period during which the human brain is developing and refining complex skills such as speech.28 

The age range of the start of stuttering is between 2 and 9 years old. At the age of 6, 80-90% of these children typically begin to have symptoms of stuttering.10 

This type of stuttering disorder is not always long-term – up to 75% of cases can resolve spontaneously without intervention. In the remaining 25% of cases of developmental stuttering, it persists into adulthood.28

Neurogenic stuttering

Neurogenic stuttering is a type of acquired stuttering and can occur in both adults and children. Neurogenic stuttering can be caused by neurodegenerative disorders such as Parkinson’s disease, traumatic brain injury, stroke, seizure disorders, multiple sclerosis, and drug use. 

Stuttering results when the damaging injury or condition affects the areas of the brain connected with speech production. Whether or not neurogenic stuttering is curable depends on the cause, the extent of damage, and whether the person responds positively to the treatment given.29


If you are concerned about stuttering for yourself or a loved one, consult your healthcare provider so they can assess your case.

It is likely the individual with a stutter will be referred to a speech and language therapist (SLT), who will work with the person to find ways to improve their speech fluency and diminish the impact that stuttering has on their life. 

A thorough assessment (according to studies) looks at: 

  • the background and historical information relevant to the stuttering 
  • the person’s speech and language development 
  • the person’s fluency of speech and stuttering characteristics 
  • the response to the stuttering by the sufferer and other people 
  • the negative effects on all areas as a consequence of the stuttering30

Treatment and management of stuttering

Techniques and strategies

Studies indicate that current strategies mostly focus on “fluency-shaping” interventions, which have the goal of improving a person’s motor/speech skills (e.g., the Lidcombe or the Camperdown Program). This sort of strategy looks at slowing the rhythm of speech and its delivery and trying to manage the dysfluencies in a more conducive manner.28

Cognitive-based strategies, such as cognitive behavioural therapy (CBT), and mindfulness-based interventions, such as acceptance and commitment therapy (ACT), have shown themselves useful for reducing anxiety, improving attitudes about stuttering, and reducing the adverse effects of stuttering for both children and adults.31

In addition, the evidence indicates that people who stutter have previously benefited psychologically from participating in self-help/support groups where they can potentially connect empathically with other people while sharing their personal experiences.32

Various approaches to stuttering treatment have proven to be more successful for younger individuals than for adults who stutter. This is believed to be because children’s brain networks can be modified through growth and reorganisation, as opposed to adults’ brains which are fully developed.33 Therefore, this adds weight to the importance of seeking support for stuttering as early as possible.


Stuttering is the most common type of speech disorder; it causes involuntary speech disturbances such as repetition, blocks, and prolonging words. Stuttering’s exact cause is still unknown but probably involves a combination of genetic, neurological, and environmental factors. There are two types of stuttering, developmental and neurogenic, and stuttering can physically and mentally affect anyone of any age.

Stuttering affects those AMAB more than those AFAB and, typically, the chances of stuttering being resolved are improved if the dysfluencies are identified early. Even though stuttering might not always be curable, it can hopefully be managed with speech and language interventions, which aim to help the speaker communicate more easily and confidently.


  1. Kang C. Progress, challenges, and future perspectives in genetic researches of stuttering. Journal of Genetic Medicine [Internet]. 2021 Dec 31 [cited 2023 Oct 20];18(2):75–82. Available from: http://www.e-kjgm.org/journal/view.html?doi=10.5734/JGM.2021.18.2.75
  2. Polikowsky HG. Genetic etiology of developmental stuttering [Internet] [Thesis]. 2022 [cited 2023 Oct 21]. Available from: https://ir.vanderbilt.edu/handle/1803/17873
  3. Herring C, Yaruss JS. The importance of understanding the broader experience of stuttering. Dev Med Child Neurol [Internet]. 2022 Oct [cited 2023 Oct 13];64(10):1188–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9544414/
  4. Junuzovic-Zunic L, Sinanovic O, Majic B. Neurogenic stuttering: etiology, symptomatology, and treatment. Med Arch [Internet]. 2021 Dec [cited 2023 Oct 14];75(6):456–61. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8802677/
  5. Choo AL, Greenberg D, Li H, Talwar A. Rate of stuttering and factors associated with speech fluency characteristics in adult struggling readers. J Learn Disabil [Internet]. 2023 Jan [cited 2023 Oct 17];56(1):7–24. Available from: http://journals.sagepub.com/doi/10.1177/00222194221095265
  6. Boyce JO, Jackson VE, Van Reyk O, Parker R, Vogel AP, Eising E, et al. Self‐reported impact of developmental stuttering across the lifespan. Develop Med Child Neuro [Internet]. 2022 Oct [cited 2023 Oct 18];64(10):1297–306. Available from: https://onlinelibrary.wiley.com/doi/10.1111/dmcn.15211
  7. Discovery of 36 loci significantly associated with stuttering [Internet]. 2023 [cited 2023 Oct 19]. Available from: https://www.researchsquare.com
  8. Bayerl SP, Gerczuk M, Batliner A, Bergler C, Amiriparian S, Schuller B, et al. Classification of stuttering – The ComParE challenge and beyond. Computer Speech & Language [Internet]. 2023 Jun 1 [cited 2023 Oct 16];81:101519. Available from: https://www.sciencedirect.com/science/article/pii/S0885230823000384
  9. Alsulaiman R, Harris J, Bamaas S, Howell P. Identifying stuttering in arabic speakers who stutter: development of a non-word repetition task and preliminary results. Frontiers in Pediatrics [Internet]. 2022 [cited 2023 Oct 16];10. Available from: https://www.frontiersin.org/articles/10.3389/fped.2022.750126
  10. Maguire GA, Nguyen DL, Simonson KC, Kurz TL. The pharmacologic treatment of stuttering and its neuropharmacologic basis. Frontiers in Neuroscience [Internet]. 2020 [cited 2023 Oct 21];14. Available from: https://www.frontiersin.org/articles/10.3389/fnins.2020.00158
  11. Sheikh SA, Sahidullah M, Hirsch F, Ouni S. Machine learning for stuttering identification: Review, challenges and future directions. Neurocomputing [Internet]. 2022 Dec 1 [cited 2023 Oct 16];514:385–402. Available from: https://www.sciencedirect.com/science/article/pii/S0925231222012772
  12. Almudhi A, Gabr SA. Associations between glutamic acid decarboxylase antibodies, oxidative stress markers, and cognitive capacity in adolescents who stutter. Saudi Journal of Biological Sciences [Internet]. 2023 Mar 1 [cited 2023 Oct 19];30(3):103580. Available from: https://www.sciencedirect.com/science/article/pii/S1319562X23000256
  13. Moein N, Rostami R, Mohamadi R, Zomorrodi R, Nitsche M, Ostadi A, et al. Electrophysiological correlates of stuttering severity: An ERP study. Journal of Clinical Neuroscience [Internet]. 2022 Jul 1 [cited 2023 Oct 21];101:80–8. Available from: https://www.sciencedirect.com/science/article/pii/S0967586822001205
  14. Frigerio-Domingues CE, Gkalitsiou Z, Zezinka A, Sainz E, Gutierrez J, Byrd C, et al. Genetic factors and therapy outcomes in persistent developmental stuttering. Journal of Communication Disorders [Internet]. 2019 Jul 1 [cited 2023 Oct 21];80:11–7. Available from: https://www.sciencedirect.com/science/article/pii/S002199241830162X
  15. Pinto GC, Juste F, Costa JB, Ritto AP, Andrade CRF de. The influence of heredity on the predictor variables of chronic developmental stuttering. Audiol, Commun Res [Internet]. 2021 Dec 20 [cited 2023 Oct 21];26:e2457. Available from: https://www.scielo.br/j/acr/a/3bLQfYxk7q3vbNmMjYm8yYz/?format=html&lang=en
  16. Walsh B, Christ S, Weber C. Exploring relationships among risk factors for persistence in early childhood stuttering. J Speech Lang Hear Res [Internet]. 2021 Aug 9 [cited 2023 Oct 24];64(8):2909–27. Available from: http://pubs.asha.org/doi/10.1044/2021_JSLHR-21-00034
  17. Choo AL, Smith SA, Li H. Associations between stuttering, comorbid conditions and executive function in children: a population-based study. BMC Psychol [Internet]. 2020 Oct 31 [cited 2023 Oct 21];8(1):113. Available from: https://doi.org/10.1186/s40359-020-00481-7
  18. Executive function - an overview | sciencedirect topics [Internet]. [cited 2023 Oct 21]. Available from: https://www.sciencedirect.com/topics/psychology/executive-function
  19. Gerlach-Houck H, Kubart K, Cage E. Concealing stuttering at school: “when you can’t fix it…the only alternative is to hide it”. LSHSS [Internet]. 2023 Jan 17 [cited 2023 Oct 21];54(1):96–113. Available from: http://pubs.asha.org/doi/10.1044/2022_LSHSS-22-00029
  20. Constantino CD. Fostering positive stuttering identities using stutter-affirming therapy. LSHSS [Internet]. 2023 Jan 17 [cited 2023 Oct 21];54(1):42–62. Available from: http://pubs.asha.org/doi/10.1044/2022_LSHSS-22-00038
  21. Nonis D, Unicomb R, Hewat S. Parental perceptions towards childhood stuttering in Sri Lanka. Journal of Communication Disorders [Internet]. 2022 Jan 1 [cited 2023 Oct 21];95:106162. Available from: https://www.sciencedirect.com/science/article/pii/S002199242100085X
  22. Costa JB, Ritto AP, Juste F, Sassi FC, de Andrade CRF. Risk factors for the development of persistent stuttering: what every pediatrician should know. International Journal of Environmental Research and Public Health [Internet]. 2022 Jan [cited 2023 Oct 23];19(9):5225. Available from: https://www.mdpi.com/1660-4601/19/9/5225
  23. Eggers K, Van Eerdenbrugh S, Byrd CT. Speech disfluencies in bilingual Yiddish-Dutch speaking children. Clinical Linguistics & Phonetics [Internet]. 2020 Jun 2 [cited 2023 Oct 24];34(6):576–92. Available from: https://www.tandfonline.com/doi/full/10.1080/02699206.2019.1678670
  24. Neef NE, Korzeczek A, Primaßin A, Wolff Von Gudenberg A, Dechent P, Riedel CH, et al. White matter tract strength correlates with therapy outcome in persistent developmental stuttering. Human Brain Mapping [Internet]. 2022 Aug [cited 2023 Oct 24];43(11):3357–74. Available from: https://onlinelibrary.wiley.com/doi/10.1002/hbm.25853
  25. Almudhi A. Evolution in technology and changes in the perspective of stuttering therapy: A review study. Saudi Journal of Biological Sciences [Internet]. 2021 Jan 1 [cited 2023 Oct 24];28(1):623–7. Available from: https://www.sciencedirect.com/science/article/pii/S1319562X20305374
  26. Nemati S, Badri R, Vahedi S, Bardel M. The effectiveness of acceptance and commitment program on social anxiety and academic resilience of students with stuttering disorder. Psychology of Exceptional Individuals [Internet]. 2023 Mar 21 [cited 2023 Oct 24];13(49):119–45. Available from: https://jpe.atu.ac.ir/article_15465_en.html
  27. Briley PM, Gerlach H, Jacobs MM. Relationships between stuttering, depression, and suicidal ideation in young adults: Accounting for gender differences. Journal of Fluency Disorders [Internet]. 2021 Mar 1 [cited 2023 Oct 24];67:105820. Available from: https://www.sciencedirect.com/science/article/pii/S0094730X20300759
  28. Busan P, Moret B, Masina F, Del Ben G, Campana G. Speech fluency improvement in developmental stuttering using non-invasive brain stimulation: insights from available evidence. Frontiers in Human Neuroscience [Internet]. 2021 [cited 2023 Oct 24];15. Available from: https://www.frontiersin.org/articles/10.3389/fnhum.2021.662016
  29. Nikvarz N, Sabouri S. Drug-induced stuttering: A comprehensive literature review. World J Psychiatry [Internet]. 2022 Feb 19 [cited 2023 Oct 24];12(2):236–63. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8900588/
  30. Brundage SB, Ratner NB, Boyle MP, Eggers K, Everard R, Franken MC, et al. Consensus guidelines for the assessments of individuals who stutter across the lifespan. Am J Speech Lang Pathol [Internet]. 2021 Nov 4 [cited 2023 Oct 24];30(6):2379–93. Available from: http://pubs.asha.org/doi/10.1044/2021_AJSLP-21-00107
  31. Connery A, Cavanna AE, Coleman R. Can Stoicism inspire stuttering intervention? The clinical usefulness of an ancient philosophy. Intl J Lang & Comm Disor [Internet]. 2023 May [cited 2023 Oct 25];58(3):977–87. Available from: https://onlinelibrary.wiley.com/doi/10.1111/1460-6984.12832
  32. Iimura D, Ishida O. The influence of self-help/support group experience on people who stutter: a systematic review. Speech, Language and Hearing [Internet]. 2022 Nov 1 [cited 2023 Oct 25];1–10. Available from: https://www.tandfonline.com/doi/full/10.1080/2050571X.2022.2139954
  33. Almudhi A, Gabr SA. Green tea consumption and the management of adrenal stress hormones in adolescents who stutter. Biomedical Reports [Internet]. 2022 Apr 1 [cited 2023 Oct 24];16(4):1–9. Available from: https://www.spandidos-publications.com/10.3892/br.2022.1515
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.

Catrin Emily Jones

Bachelor of Science - BS, Psychiatric/Mental Health Nurse/Nursing, Swansea University

Cat is a qualified mental health nurse who has worked across multiple sectors, such as hospital wards and in the community. Cat has several years of experience in geriatric nursing, specifically dementia care. She is bilingual and is fluent in both the English and Welsh languages.

Leave a Reply

Your email address will not be published. Required fields are marked *

my.klarity.health presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818