When a person is unable to produce speech sounds correctly or fluently then he or she has a speech disorder. Speech sound disorders include problems with articulation (making sounds), phonological processes (making sound patterns) and stuttering (ASHA).
Articulation disorders involve problems making sounds. Phonological disorders involve difficulty with making speech sound patterns. Sounds can be substituted, left off, added or changed. These errors may make it hard for people to understand you.
Dysarthria is a motor speech disorder. The muscles of the mouth, face, and respiratory system may become weak, move slowly, or not move at all after a stroke or other brain injury.
Apraxia of speech is a motor speech disorder. People with apraxia of speech have trouble sequencing the sounds in syllables and words.
Stuttering is a speech disorder in which sounds, syllables, or words are repeated or last longer than normal. These problems cause a break in the flow of speech (called disfluency).
Swallowing disorders (dysphagia) are difficulties with chewing and/or swallowing foods or liquids which may lead to poor nutrition or dehydration, less enjoyment of eating or drinking or embarrassment or isolation in social situations involving eating.