Aphasia meaning in medical terms
Doctors and speech-language pathologists define aphasia as an acquired language disorder caused by damage to the brain. Each part of that phrase matters:
- Acquired means it happens after a person has already learned to speak and understand.
- Language means the system of words and grammar we use to talk, listen, read and write. It is not the same as the voice or the muscles of the mouth.
- Damage to the brain is usually in the left side, where language is handled for most people. A stroke is the most common cause.
The word comes from Greek: a- means “without” and phasis means “speech.” Some doctors, especially outside the United States, say dysphasia. The two words describe the same disorder (see aphasia vs. dysphasia).
What aphasia can affect
Aphasia looks different from person to person. It can affect one skill more than another:
- Speaking: finding the right word, naming people or things, or putting words into sentences.
- Understanding: following what other people say, especially fast talk, long sentences or group conversations.
- Reading: making sense of written words, signs, menus or forms.
- Writing and typing: spelling words or putting thoughts on paper.
Some people have mild aphasia and mostly struggle to find names. Others can barely speak or understand. The types of aphasia describe these patterns.
What aphasia is not
- It is not a loss of intelligence. People with aphasia usually think, remember and decide as they did before.
- It is not hearing loss, though it can be mistaken for it.
- It is not confusion. A person can know exactly what is going on and still not find the words.
- It is not the same as slurred speech from weak muscles (dysarthria) or trouble planning mouth movements (apraxia of speech), though these can happen together with aphasia.
What is the inability to speak called?
People often search for one word for “can't speak.” The right word depends on what is getting in the way:
| Term | What is affected |
|---|---|
| Aphasia | Language: finding, using or understanding words |
| Apraxia of speech | Planning the mouth movements needed to say words |
| Dysarthria | The strength and control of the muscles used for speech |
| Aphonia | The voice itself: a person cannot make a voice, often from a throat problem |
| Mutism | Not speaking at all; it has many possible causes |
Only a doctor or a speech-language pathologist can tell which one a person has. If speaking suddenly becomes hard, treat it as an emergency and call 911.
How aphasia is diagnosed
Aphasia is often first noticed by the doctor treating a stroke or head injury. A brain scan, such as a CT or MRI, can show where the brain was hurt. A speech-language pathologist then tests how well the person speaks, understands, reads and writes, and builds a therapy plan from what they find.
Common questions
What does aphasia mean in medical terms?
In medical terms, aphasia is an acquired language disorder caused by damage to the brain, usually on the left side. Acquired means it happens after a person has already learned language. It can affect speaking, understanding, reading and writing.
What is the inability to speak called?
There is no single word. If the problem is with language, it is aphasia. If the brain cannot plan the mouth movements for speech, it is apraxia of speech. Weak speech muscles cause dysarthria. Losing the voice itself is called aphonia, and not speaking at all is called mutism.
Is aphasia a disease?
Aphasia is not a disease on its own. It is a condition caused by damage to the brain, and doctors often treat it as a sign of another problem, such as a stroke, a head injury, a brain tumor or a progressive brain condition.
Does aphasia affect intelligence?
No. Aphasia affects language, not intelligence. Most people with aphasia still think clearly, remember, recognize people and make their own decisions. They have trouble with words, not ideas.
How common is aphasia?
About 2 million people in the United States live with aphasia, according to the National Aphasia Association. Stroke is the leading cause, and about one in three stroke survivors has aphasia.
How ExpressAgain can help
Many people with aphasia can still recognize the words they mean, even when they cannot say them. ExpressAgain lets a person read and choose what they want to say, from basic needs to questions for the doctor, and then says it out loud so the people around them can understand.
Keep reading
More about aphasia
- Understanding aphasia: the overview
- Types of aphasia: Broca's, Wernicke's and global aphasia, plus anomic, conduction, transcortical and primary progressive aphasia.
- Aphasia vs. dysphasia: Two words for one language disorder, and why dysphagia (swallowing) is something else.
- Aphasia causes: Stroke, head injury, tumors, infections and progressive conditions, and why sudden changes are an emergency.
- Can aphasia be cured?: Recovery, speech-language therapy and what to expect, including primary progressive aphasia.
- ExpressAgain for aphasia: how the app's aphasia mode works
- ExpressAgain after a stroke: communication through recovery
Sources
- NIDCD (National Institutes of Health): Aphasia
- National Aphasia Association: What Is Aphasia?
- National Aphasia Association: Glossary of Aphasia Terms
- American Speech-Language-Hearing Association (ASHA): Aphasia, Practice Portal
- MedlinePlus (National Library of Medicine): Aphasia
- Mayo Clinic: Aphasia, symptoms and causes
- Cleveland Clinic: Aphasia
Last reviewed . This page is general information written in plain language from the sources above. It is not medical advice and cannot diagnose anyone. Talk with a doctor or a speech-language pathologist about your own situation. If speaking or understanding suddenly becomes hard, call 911.