Parents who notice a persistent stuttering problem are often urged to bring the fact to a physician’s attention before the child’s third birthday. If a child is still stuttering by age 5, medical attention is even more strongly recommended. If a stuttering problem appears to be evident, the child may be referred to a speech-language pathologist who will further test the child’s speaking ability.

The speech-language pathologist will first obtain a detailed history of the condition (e.g., when it was first noticed, the circumstances under which it occurs), followed by a complete evaluation of speech and language abilities. This includes observing  the patient’s speech and looking for patterns of dysfluencies. Speech rate and language skills tests may also be performed, and details about environmental factors that affect the patient’s stuttering (e.g., how teasing or speaking in public influence speech patterns) will be noted.

In some cases, an audiologist (a specialist in hearing problems) may be consulted to test the child’s hearing, as children who cannot hear well may have increased difficulty hearing themselves and pronouncing words correctly.

In children younger than 5, it can be difficult to decide whether or not the child is likely to outgrow stuttering over time or whether the child needs treatment. Factors that may indicate a likely need for treatment include a family history of stuttering, stuttering symptoms that have lasted for at least six months and the presence of other speech or language disorders. Patients older than age 5 who stutter significantly are usually considered to be candidates for treatment.

In cases in which stuttering occurs following a head injury, or appears in advanced ages, it is necessary for a physician to perform a complete physical examination and compile a thorough medical history. Further tests (e.g. brain imaging) may be necessary to diagnose probable neurological problems such as stroke.