Guides
Dysarthria, apraxia or aphasia? The difference in plain words, from Speech Assistant
The Speech Assistant Team
October 2026 · 2 min read
Aphasia is a language disorder, dysarthria is a weakness or poor control of the speech muscles, and apraxia of speech is a difficulty planning the movements for speech.
What is aphasia?
- Damage to the brain's language areas, most often after a stroke.
- It can affect speaking, understanding, reading and writing.
- The person knows what they mean, but the words are hard to find or come out wrong.
- Intelligence is not affected.
What is dysarthria?
- A motor speech disorder: the muscles of the lips, tongue, voice or breathing are weak, slow or poorly coordinated.
- Speech can sound slurred, quiet, slow or nasal.
- Language itself is usually intact: the person can often read and write normally.
- Causes include stroke, brain injury, Parkinson's, ALS/MND and cerebral palsy.
What is apraxia of speech?
- The muscles work, but the brain has trouble planning and sequencing speech movements.
- Errors are inconsistent: a word may come out right once and wrong the next time.
- Longer words are harder; the person may grope for the right mouth position.
- In adults it often follows a stroke; childhood apraxia of speech is a developmental form.
How can you tell them apart?
- Aphasia: wrong or missing words; reading and writing are often affected too.
- Dysarthria: the right words, but slurred or quiet; errors are consistent; reading and writing usually fine.
- Apraxia: the right words, but sounds come out in the wrong order or differently each time; reading and writing usually fine.
Only a speech-language therapist can assess which one (or which mix) a person has.
How can AAC help?
- Aphasia: picture phrases and ready-made sentences reduce the need to find each word.
- Dysarthria: typing to speak works well, because spelling is usually intact.
- Apraxia: a tap-to-speak board gives a reliable backup when speech won't come.
In Speech Assistant, starter boards (Needs, Feelings, Questions) work after Continue as Guest, the keyboard has word prediction, and Show puts a message full screen.
Speech Assistant is a communication tool, not a medical device. Work with the person's speech-language therapist.
Next: AAC app for aphasia after a stroke and communication boards for adults.
Questions people ask
What is the main difference between aphasia and dysarthria?
Aphasia is a language problem: finding, understanding, reading or writing words. Dysarthria is a muscle problem: the words are there, but the speech muscles are weak or poorly controlled.
Is apraxia of speech the same as dysarthria?
No. In apraxia the muscles are not weak; the brain has trouble planning and sequencing the movements for speech.
Can someone have more than one?
Yes. After a stroke or brain injury, aphasia and apraxia or dysarthria often occur together. A speech-language therapist can tell which ones are present.
Can AAC help with all three?
AAC can support communication in each case, but the best setup differs. A speech-language therapist can help choose it.
Speech Assistant - AAC Pad
Free AAC for iPhone, iPad and Apple Watch.
