Fluency Disorders in Children and Adults: Symptoms, Diagnosis, and Treatment

Amanda Unrau
M.A. CCC-SLP
11/03/26 | Last modified: 11/03/26

Fluency of speech is the progression, smoothness, rate, and effort of speech production. Fluency disorders affect the natural flow, rhythm, and rate of speech. With fluency, speech production seems effortless. With a fluency disorder, speech is often effortful. These disorders can impact communication, but they are common and manageable. This article covers the types, signs, causes, diagnosis, treatment, and support of fluency disorders. 

What Are Fluency Disorders?

Fluency disorders are interruptions to the flow of speech that impact its rate, rhythm, and effort. Everyone is disfluent at times. Examples of disfluencies include using filler words (e.g., “um,” “uh,” “like”), repeating words or phrases, or hesitating when speaking. 

Disfluencies become a fluency disorder when they negatively affect the effectiveness and efficiency of communication. According to ASHA, fluency disorders are accompanied by secondary characteristics, such as physical tension or eye blinking. Typical disfluency does not include associated behaviors. Typical disfluencies usually do not lead to negative reactions, but those with fluency disorders can become frustrated or upset. 

Types Of Fluency Disorders

When people think of fluency disorders, they tend to only think of stuttering, but there are actually two main types of fluency disorders. The two types of fluency disorders are stuttering and cluttering.

Stuttering

Stuttering is a fluency disorder that is characterized by interruptions to the flow of speech. Stuttering is the most common type of fluency disorder. It often includes a negative reaction from fluent speakers to the person who stutters. The person who stutters often also has a negative view of their own speech. 

Stuttering impacts the rate and rhythm of speech. It includes whole word repetitions (e.g., “Who-who-who are you?”), partial word or sound/syllable repetitions (e.g., “Where are we g-g-g-going?”), prolongation of sounds (e.g., “You can ssssssit here.”), and blockages, which are silent pauses when attempting to initiate sounds. 

Cluttering

Cluttering is a fluency disorder that is characterized by nonstuttering disfluencies (e.g., um, uh, like), a rapid or irregular rate of speech, and irregular pauses that make the speech sound jerky. The speech of someone who exhibits cluttering sounds unclear and disorganized. Cluttering includes jammed or merged words, where sounds are blended too much to the point that some syllables are missing (e.g., “hapness” for “happiness”). 

With stuttering, the individual knows what they want to say, but they are unable to say it at that moment. With cluttering, the breaks in speech make it sound like the speaker doesn’t know what they want to say or they have difficulty planning their speech. 

Signs And Symptoms Of Fluency Disorders

There are specific signs and symptoms that indicate a fluency disorder is present. These can include disfluencies as well as secondary behaviors that can accompany moments of stuttering. 

Signs and Symptoms of Stuttering and Cluttering

Signs and symptoms of stuttering include:

• Whole-word, part-word, or sound/syllable repetitions

• Prolongation of sounds

• Blocks that cause inaudible pauses or difficulty starting sounds

• Producing words with excess struggle or physical tension

Signs and symptoms of cluttering include:

• Rapid or irregular rate of speech

• Frequent nonstuttering disfluencies

• Atypical pauses leading to unusual prosody

• Overly coarticulated speech leading to deletion of syllables and word endings

• Frequent change in topics 

Secondary Behaviors

There are a few types of secondary related behaviors that can accompany stuttering. 

Secondary stuttering, or concomitant stuttering, is a group of behaviors that accompany stuttering. These behaviors are not necessarily an attempt to prevent stuttering. Sometimes these behaviors are very subtle, and at times they are highly noticeable. The person who stutters may not be aware of them. Secondary behaviors include:

• Nodding the head, tapping the feet, or clenching the fists

• Blinking the eyes or tightening the jaw

• Clearing the throat

Avoidance behaviors are an attempt to conceal stuttering. They happen right before a moment of disfluency. Avoidance behaviors include:

• Using filler words

• Avoiding certain sounds or words

• Substituting words

• Adding unnecessary words

• Circumlocution, or talking around a word or topic

Escape behaviors are an attempt to stop stuttering as it is happening. These happen during a moment of disfluency. Escape behaviors can include any of the secondary stuttering or avoidance behaviors. There can be an overlap among the three secondary behaviors. The type of behavior depends on the timing of the behavior and the speaker’s intent. 

What Causes Fluency Disorders?

The exact cause of fluency disorders is not known, but researchers point to multiple factors, including genetic and neurological factors. 

Genetics may play a role in whether someone will stutter or not. Individuals with family members who stutter are more likely to stutter. According to ASHA, studies have shown structural and functional neurological differences in children who stutter. 

Certain factors can increase symptoms of fluency disorders. These can include speaking demands and environmental factors, such as family dynamics, stress, and anxiety. These factors may increase disfluencies and increase an individual’s internal negative reactions to their own stuttering. A sensitive temperament in young children is associated with persistent stuttering and difficulty coping with disfluencies. 

Children who start stuttering at 3.5 years of age or later, stutter for more than 6 to 12 months, have a family history of persistent stuttering, or have slow rates of language development or a co-occurring speech or language impairment have a greater likelihood that their stuttering will become persistent. Boys are also more likely to develop persistent stuttering than girls.

Fluency Disorders In Children And Adults

Fluency disorders differ across the lifespan. Both children and adults can stutter, but it may happen for different reasons and can present itself in different ways. 

Some young children experience developmental disfluency as they learn to communicate. Children between the ages of 2 and 5 are learning how to accurately produce words and sounds smoothly. Their coordination skills may have a hard time keeping up with all the new words they are learning and the longer sentences they are forming. These common disfluencies are developmentally normal.

True fluency disorders typically develop in childhood. Most children with a fluency disorder begin stuttering before age 4. The average age of onset of stuttering is about 33 months. The onset of a fluency disorder may be sudden or develop slowly over time. Sometimes children may begin to exhibit disfluencies, stop for several weeks or months, and then begin stuttering again. Many children do grow out of their fluency disorder. Children who begin stuttering before 3.5 years of age are more likely to grow out of it. If stuttering lasts longer than 6 to 12 months or worsens, recovery without intervention is less likely. 

Adults with fluency disorders have often stuttered since they were children, but it is possible for adults to develop a fluency disorder later in life. Stuttering may develop after a traumatic event, such as a major accident or the loss of a loved one. Adults can also acquire neurogenic stuttering. This happens when there is damage to the part of the brain responsible for language, such as after a stroke or brain injury. Emotional trauma can lead to psychogenic stuttering. 

How Are Fluency Disorders Diagnosed?

Fluency disorders are diagnosed through assessment conducted by a speech-language pathologist when a fluency disorder is suspected. The main components of a fluency disorder assessment include the following: 

• Fluency-related background information: medical history, educational records, age of disfluency onset, patterns of disfluency, rating of the severity of disfluency

• Speech and language development: proficiency in each language the child is exposed to, family history of fluency disorders, speech and language concerns

• Fluency behaviors: speech sample analysis inside and outside the clinical setting, assessment of speech fluency (frequency, type, and duration of disfluencies), presence of secondary behaviors 

• Reactions to the client’s disfluencies by listeners: consultation with family members, teachers, and other professionals

• The client’s reactions to their own disfluencies: determination of the child’s awareness of their disfluencies, identification of the client’s strengths and coping strategies

• Any adverse impact caused by the disfluencies: assessment of internal reactions and emotional and cognitive impact

Cluttering is typically not diagnosed until a child is about 8 years old. This is when a child’s language becomes complex enough that symptoms stand out, even though the onset of cluttering may be as young as 33 months old. 

Following an assessment, the speech therapist will give their recommendation on whether to pursue treatment or not. If intervention is not needed at that time, the SLP may instead advise the child’s caregivers to monitor their child’s fluency and possibly have them reevaluated in the future. 

Early assessment of fluency disorders in children is important. Speech-language pathologists can make recommendations such as direct treatment or parent-led programs. Starting intervention can help to reduce the severity of disfluencies and prevent long-term persistent stuttering. 

Treatment And Management Of Fluency Disorders

Following a fluency disorder diagnosis, there are a variety of treatment approaches to consider. Fluency disorders cannot be cured, but they can be managed. A speech-language pathologist will make appropriate recommendations and guide treatment. Treatment is highly individualized and dependent on the individual’s communication environment and any coexisting disorder that impacts the fluency disorder. 

Indirect Treatment

The focus of indirect treatment is to help family members change their own speech and make modifications to the environment. The goal is to promote calm and effortless communication and reduce negative internal reactions. Changes family members may make can include:

• Reducing their rate of speech

• Modeling fluent speech

• Indirectly gathering information instead of asking direct questions

• Focusing on what the child says instead of how they say it

Direct Treatment

The focus of direct treatment is changing the child’s attitudes and opinions of their stuttering. The goal is to improve communication and reduce negative internal reactions. Specific treatment approaches may attempt to reduce stuttering, whereas other methods attempt to build confidence, even when stuttering is present. Examples of direct treatment include:

• Reducing the rate of speech

• Holding out syllables

• Modifying a word that was stuttered

Operant Treatment

Operant treatment is based on the principles of operant conditioning. This involves using positive and negative reinforcement to modify behavior. The speech therapist trains caregivers to positively reinforce fluent speech and negatively reinforce disfluent speech in order to increase fluent speech. 

Speech Modification

Speech modification strategies are a treatment approach used to change the timing and tension of speech or change the pausing between syllables and words. These strategies, also called fluency shaping, are used whether or not speech is expected to be fluent. Speech modifications include:

• Easy onset: gradually easing into voicing, especially on initial vowels

• Light contact: gentle touching of the articulators to reduce tension and pressure 

• Continuous phonation: maintaining voicing throughout a specified utterance

• Stretched syllables: prolonging each syllable

• Reduced rate: slowing the rate of speech

Stuttering Modification 

Stuttering modification strategies are used to reduce physical tension and effort. The individual will choose a strategy to help them, either before, during, or after a moment of disfluency, in order to reduce the tension. Stuttering modification strategies follow a hierarchy from easier speaking situations, such as speaking with a friend, to more challenging speaking situations, such as giving a speech or calling customer service on the phone. Stuttering modification strategies include:

• Preparatory set: using stuttering modification strategies when a moment of stuttering is anticipated in order to control the stutter

• Pull-out: sliding out of a stuttered word by adjusting voicing and airflow to stutter without tension or effort

• Cancellation: pausing after a stuttered word to adjust airflow and voicing in order to produce the word again

Strategies to Decrease Negative Reactions 

Several strategies can be used to help reduce negative internal reactions to stuttering. These encompass both personal and environmental considerations. Strategies include:

• Awareness and identification: discussing one’s experience with stuttering and anxiety and watching recordings of their own stuttering to increase self-awareness

• Desensitization: participating in pseudostuttering (voluntary stuttering) to confront fears in structured environments in order to reduce anxiety 

• Cognitive Restructuring: identifying thoughts, attitudes, and emotional reactions to help speakers change the way they think about themselves and their stuttering

• Self-Disclosure: communicating information about stuttering or revealing one’s identity as a person who stutters 

Delayed Auditory Feedback

Research has been conducted showing that some individuals who stutter may benefit from delayed auditory feedback. Delayed auditory feedback occurs when an individual wears headphones that play their voice back a fraction of a second later. This delay can help to improve fluency and slow the rate of speech. 

Cluttering Treatment

Treatment of cluttering teaches individuals strategies to modify cluttering. Some of the stuttering treatment approaches are not suitable for cluttering. Cluttering treatment strategies include:

• Emphasizing multisyllabic words and word endings

• Recognizing communication breakdowns

• Adjusting the rate of speech and adding pauses

When To See A Speech-Language Pathologist

Speech therapy can help individuals improve their fluency skills and decrease avoidance behaviors and negative reactions surrounding stuttering. When is a speech therapy evaluation needed? If you notice any of the following signs, reach out to a licensed speech-language pathologist.

• Repetitions, prolongations, or blocks in daily speech

• Lack of confidence

• Avoidance of talking

• Avoidance of certain words 

• Abnormal body movements while speaking

• Becoming out of breath while speaking

• Stuttering that lasts longer than 3 to 6 months

Contact a speech therapist for a professional assessment when you observe any of these signs. The earlier you reach out for help, the sooner speech therapy can help to improve fluency. Keep in mind that this article is for educational purposes and is not diagnostic.

How Forbrain Can Support Speech Fluency

Forbrain is an auditory stimulation tool that can be used alongside speech therapy in order to support speech fluency. The Forbrain headset has been shown to be an effective auditory feedback device. Through bone conduction technology, the individual hears their own voice after a delay, which may reduce moments of disfluency. This promotes smoother speech that is produced at a slower rate. Besides promoting fluent speech in the moment it is worn, Forbrain for Stuttering is designed to support fluency and build progress over time.   

Forbrain is not a treatment or cure, and should be used as a tool alongside professional therapy. It should not replace professional evaluation or therapy when concerns are significant. 

Bottom Line

Fluency disorders impact the flow of communication and can lead to a lack of confidence and avoidance of speaking. Thankfully, individuals can learn strategies to help with their stuttering and cluttering. Fluency disorders can occur in children and adults, and they are manageable across the lifespan. It is important to have a good understanding of stuttering so you know when to reach out for help. A full assessment with a speech-language pathologist is the first step toward identifying a fluency disorder and starting a treatment plan. The sooner you learn to manage a stutter, the better. 

References

American Speech-Language-Hearing Association. (n.d.). Stuttering, cluttering, and fluency. Retrieved October 21, 2026, from https://www.asha.org/practice-portal/clinical-topics/fluency-disorders/

American Speech-Language-Hearing Association. (n.d.). Characteristics of typical disfluency and stuttering. Retrieved October 24, 2026, from https://www.asha.org/practice-portal/clinical-topics/fluency-disorders/characteristics-of-typical-disfluency-and-stuttering/

Escera, C., López-Caballero, F., & Gorina-Careta, N. (2018). The potential effect of Forbrain as an altered auditory feedback device. Journal of Speech, Language, and Hearing Research, 61(4), 801-810.

St. Louis, K. O. (n.d.). Cluttering. The Stuttering Foundation. Retrieved October 25, 2026, from https://www.stutteringhelp.org/cluttering

The Stuttering Foundation. (n.d.). Delayed auditory feedback. Retrieved October 26, 2026, from https://www.stutteringhelp.org/delayed-auditory-feedback