Dysarthria and apraxia of speech can both make speech hard to understand after a stroke or brain injury, but they happen for different reasons. In dysarthria, the muscles used for speaking are weak, slow or poorly coordinated, so speech comes out slurred in much the same way every time. In apraxia of speech, the muscles work normally, but the brain has difficulty planning and sequencing the movements for speech, so the same word may come out differently on each attempt — the person often knows the word, yet cannot get it out quite right.
If someone you love has been given one of these terms — or if both have been mentioned and you are unsure which is which — you are not alone. The two are often confused, because they can sound similar and sometimes occur together. The difference matters, though, because assessment and therapy are shaped around what is actually causing the difficulty. This guide explains each difficulty in plain language, sets them side by side, and describes how a speech and language therapist can tell which pattern a person has. Only an assessment can do that for an individual; this guide is a starting point for understanding, not a way to decide for yourself.
Key Takeaways
- Dysarthria is a difficulty with the muscles of speech: weakness, slowness or poor coordination makes speech slurred in much the same way each time.
- Apraxia of speech is a difficulty with planning speech movements: the muscles are strong enough, but sequencing the movements goes wrong, so errors change from attempt to attempt.
- In apraxia of speech, automatic phrases such as greetings and counting are often much easier than words the person is deliberately trying to say.
- The two difficulties can occur together, and either can occur alongside aphasia, a difficulty with language itself.
- Because the causes differ, therapy differs too — an assessment looks closely at the pattern of speech to work out what is going on.
On this page
- How speech happens: plan, send, move
- Dysarthria explained
- Apraxia of speech explained
- Dysarthria and apraxia of speech side by side
- Can someone have both?
- Why the difference matters
- How a therapist tells them apart
- What can help at home
- When to seek help
- Questions to ask a therapist
- Frequently asked questions
- Related guides
How speech happens: plan, send, move
Speaking feels instant, but behind every word there are three steps happening in a fraction of a second:
- Plan. The brain works out which sounds are needed, in which order, and how the mouth, tongue, lips and voice need to move to make them.
- Send. The brain sends that plan as signals along the nerves to the muscles of the lips, tongue, jaw, soft palate, voice box and chest.
- Move. The muscles carry out the plan — moving in the right sequence, with the right strength, speed and coordination to produce clear speech.
Dysarthria and apraxia of speech sit at different steps in this chain. Dysarthria is mainly a problem at the “move” stage: the plan is intact, but the muscles cannot carry it out properly. Apraxia of speech is mainly a problem at the “plan” stage: the muscles can move, but the plan itself keeps coming out muddled.
Dysarthria explained
Dysarthria happens when the muscles used for speaking become weak, stiff, slow or poorly coordinated after an injury or illness affecting the brain or the nerves that serve those muscles. Because the difficulty lies in the muscles themselves, it affects speech in a consistent way: the same kinds of errors appear again and again, in much the same pattern each time.
Speech with dysarthria may sound:
- Slurred, as if the sounds are running into one another, because the tongue and lips are not reaching their targets crisply.
- Slow and effortful, or sometimes unusually fast and hard to follow.
- Quiet or weak, if the breath and voice are affected, so the person is hard to hear across a room.
- Strained, nasal or breathy in quality, because the voice and the soft palate are part of the same muscle system.
Because the same muscles are used for other everyday movements, difficulties with chewing, managing food in the mouth or controlling saliva can occur alongside dysarthria. Not everyone has these, and swallowing needs separate assessment if there are concerns, but a therapist may well ask about eating and drinking as part of the whole picture.
The key point is the consistency. A person with dysarthria usually speaks in the same slurred pattern whether they are chatting, reading aloud or repeating a word. The difficulty does not come and go between one attempt and the next, although it can become more noticeable when the person is tired.
Apraxia of speech explained
Apraxia of speech — sometimes called acquired apraxia of speech when it begins in adulthood — is a difficulty with planning and sequencing the movements of speech. The muscles of the lips, tongue and jaw are not weak: the person can usually move them well for other purposes. What goes wrong is the brain’s programme for stringing speech movements together in the right order, at the right time.
Because the problem is in the plan rather than the muscles, the pattern looks quite different:
- Errors are inconsistent. The same word may come out in different ways on different attempts — nearly right once, quite wrong the next, then clear again.
- There may be visible or audible groping. The person may silently position their mouth, try a sound, stop, and try again — searching for the right movement, much like searching for a word, but at the level of the sounds themselves.
- Trial and error is common. The person may make several attempts at a word, sometimes getting closer each time, and they often know when an attempt has gone wrong.
- Automatic speech is often easier than deliberate speech. Phrases the person has said thousands of times — greetings, “thank you”, counting, familiar songs or sayings — may come out clearly, while a word they are consciously trying to produce gets stuck. This can puzzle families — “He said that perfectly a minute ago” — but well-worn phrases run on a kind of autopilot, while deliberate speech needs the planning system that is struggling.
- The person usually knows the word. In apraxia of speech, the language itself — the words and sentences the person wants — is often intact. They may be able to write the word down even when they cannot say it smoothly. This awareness can be deeply frustrating: the person knows exactly what they want to say and can hear their own errors.
Apraxia of speech is usually most obvious on longer words and sentences, and on sounds that need precise sequencing; short, familiar words tend to be easier.
Dysarthria and apraxia of speech side by side
The table below summarises the main differences. Real life is rarely as tidy as a table — patterns overlap, and only an assessment can judge which pattern fits a particular person — but it shows what a therapist is listening for.
| Feature | Dysarthria | Apraxia of speech |
|---|---|---|
| Underlying problem | The muscles of speech are weak, slow or poorly coordinated | The brain has difficulty planning and sequencing speech movements |
| Consistency of errors | Consistent — speech sounds slurred in much the same way each time | Inconsistent — the same word may come out differently on each attempt |
| Muscle strength | Reduced or poorly coordinated — the muscles themselves are affected | Normal — strength is fine; sequencing is the problem |
| Automatic phrases | No easier than other speech — greetings sound slurred too | Often easier — greetings, counting and familiar sayings may come out clearly |
| Groping and trial-and-error | Unusual — the person does not need to search for movements | Common — visible or audible searching, false starts and repeated attempts |
| Effect of tiredness | Speech often sounds worse when the person is tired, as the muscles fatigue | May vary; errors can increase under pressure or when rushing |
| Typical sound of speech | Slurred, slow or quiet, with a changed voice quality | Uneven — wrong sounds, jumbled order, pauses and restarts, with clearer patches |
Can someone have both?
Yes. Because a stroke or brain injury can affect more than one part of the system, a person can have dysarthria and apraxia of speech at the same time. One pattern may be much more prominent than the other, and the picture can change over time as the person recovers.
Either difficulty can also occur alongside aphasia — a difficulty with language itself, such as finding words or building sentences. This is one reason careful assessment matters: three different difficulties (language, planning, and muscle movement) can all make speech hard to follow, and each one needs its own kind of support.
Why the difference matters
The difference is not just a label — it shapes what helps.
- Assessment looks at different things. For dysarthria, a therapist pays close attention to the strength, speed and coordination of the speech muscles and to voice and breathing. For apraxia of speech, they listen to how errors change across attempts and which kinds of speech come more easily.
- Therapy works on different steps. Therapy for dysarthria generally focuses on making the most of the muscle system — for example, slowing down or placing more emphasis on clear mouth movements. Therapy for apraxia of speech generally focuses on rebuilding the plans for speech movements through structured, repeated practice of sounds, words and phrases.
- Everyday strategies differ. Advice that helps one difficulty can frustrate the other. Telling a person with apraxia of speech to “just say it again” may simply produce a different wrong version and more frustration, whereas a person with dysarthria may benefit from a reminder to slow down and try the sentence once more, steadily.
- Expectations differ. With dysarthria, families can expect the same general pattern day to day. With apraxia of speech, speech can vary a great deal within a single conversation — and that variability is part of the condition, not a sign the person is not trying.
Both difficulties can be supported, and once the pattern is identified, therapy and advice can be aimed at the step that is actually struggling. Progress varies from person to person, and there are no guarantees, but a clear picture is the best starting point.
How a therapist tells them apart
A speech and language therapist is trained to listen closely to the pattern of a person’s speech. In general terms, an assessment of motor speech usually involves:
- Listening to everyday conversation — how speech sounds in natural talk, and how well the person is understood.
- Repetition tasks — asking the person to repeat sounds, words and sentences of increasing length and complexity, and noticing whether errors stay the same or change between attempts.
- Automatic versus deliberate speech — comparing well-worn phrases, such as counting or days of the week, with words the person is asked to produce on purpose.
- Reading aloud and describing pictures, which place different demands on planning and language.
- Looking at mouth movements — asking the person to carry out movements such as opening the mouth, moving the tongue or licking the lips, to understand how the muscles are working.
- Asking about the history — when the difficulty began, what else changed at the same time, and how speech varies across the day.
The therapist weighs all of this together with the person’s wider medical picture, which is why the conclusion is an individual one. Two people whose speech sounds similar to family members may have different patterns on assessment — and the support that follows is matched to the person, not just to how their speech sounds. For general information about motor speech difficulties, the American Speech-Language-Hearing Association (ASHA) publishes plain-language pages for the public.
What can help at home
Families often ask what they can do between appointments. The details that matter most depend on the pattern, but these general ideas are a helpful starting point.
If the pattern is dysarthria:
- Encourage the speaker to slow down a little and take breaths between phrases; slower speech is usually clearer speech.
- Talk face to face, in good light, so the listener can see the speaker’s mouth as well as hear them.
- Reduce competing noise — turn the television or radio down during conversation.
- Agree that it is fine to ask for a key word to be repeated, rather than guessing.
If the pattern is apraxia of speech:
- Allow plenty of time. Rushing makes planning harder, and a calm pause often lets the word arrive.
- Resist finishing the person’s sentences unless they welcome it — being spoken over can add to the frustration of knowing the word but not reaching it.
- If a message is getting stuck, another route can help: writing a key word, pointing to a letter board, or gesturing the meaning — other ways of getting the message across while speech is being rebuilt.
- Welcome the attempts that come out well, and do not draw attention to every error — the person usually hears them already.
For both: keep conversations relaxed and unhurried, and remember that communication is a partnership — a patient listener makes a genuine difference.
When to seek help
It is worth asking for a speech and language therapy assessment if speech has become hard to understand after a stroke, brain injury or other illness, or if an existing difficulty seems to be changing. A doctor can usually advise on how assessments are arranged, or you can contact a speech and language therapist directly. It is never too late to ask.
One situation is an emergency. Sudden slurred, jumbled or unclear speech — especially together with a drooping face, weakness in an arm or leg, or sudden difficulty finding words — can be a sign of a stroke. Call your local emergency number immediately. Do not wait to see whether it passes.
Questions to ask a therapist
- Which pattern do you think is causing the difficulty — dysarthria, apraxia of speech, or a mixture — and what did you notice that points to it?
- How has language been affected, as well as speech itself?
- What will therapy focus on, and what can we practise at home between sessions?
- What should family and friends do to make conversation easier?
- How will we know whether things are changing, and when will the plan be reviewed?
Frequently asked questions
How can we tell at home which one our relative has?
You may notice clues — consistency points towards dysarthria, and changing errors with easier greetings point towards apraxia of speech — but clues are not a conclusion. The patterns can overlap, and both can sit alongside language difficulties. Only a speech and language therapy assessment, looking at the whole picture, can tell which pattern a person has.
Can apraxia of speech happen without a stroke?
Yes. Apraxia of speech can follow other kinds of brain injury or illness that affect the planning areas of the brain, as well as stroke. The important thing is not the cause but the pattern: difficulty planning speech movements with normal muscle strength.
Does dysarthria mean the person’s thinking is affected?
No. Dysarthria is a difficulty with the muscles of speech. A person with dysarthria may think, understand and know exactly what they want to say, just as before — it is the clarity of the speech itself that is affected. Separate difficulties with thinking or language can occur after the same injury, but they are assessed separately.
Why can someone with apraxia of speech sing or swear, but not say what they mean?
Highly automatic speech — familiar songs, greetings, counting, and sometimes exclamations — runs on well-practised pathways that need less deliberate planning. Speech the person is constructing in the moment relies on the planning system that apraxia affects. It is a recognised feature of the condition, not a sign that the person could “do it if they tried”.
Will speech get back to how it was?
Progress varies a great deal from person to person, and depends on the cause, the severity of the difficulty and many other individual factors. Therapy aims to make speech as clear and effective as it can be, and to build reliable ways of communicating alongside speech. No honest guide can promise a particular outcome.
Can children have these difficulties too?
Children can have motor speech difficulties, including a childhood form of apraxia of speech, and speech sound difficulties that look quite different from the adult patterns described here. This guide is about difficulties acquired in adulthood, after stroke or brain injury. If you are concerned about a child’s speech, a paediatric speech and language therapy assessment is the right first step.
Related guides
- Motor speech disorders explained: a complete guide
- Signs of dysarthria after stroke
- Aphasia: a complete guide for survivors and families
- Support for adults: the For Adults hub
- Browse all conditions and topics
A gentle next step
If speech has become hard to understand — for you, or for someone you love — understanding which pattern lies behind it is a genuinely useful first step, because it points support in the right direction. If you would like to talk about what you have noticed and what an assessment could clarify, you are very welcome to get in touch online. There is no obligation and no pressure: just a friendly first conversation, at your pace.
By Hamayal Adnan, Speech-Language Pathologist
This article is for general educational purposes only and is not medical advice. It does not replace an assessment by a qualified speech and language therapist or other healthcare professional. Every person is different. If you have concerns about speech, language, feeding or swallowing, please seek professional advice. In an emergency, call your local emergency number.