American Speech-Language-Hearing Association
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What is aphasia?

Aphasia is a disorder that results from damage to the parts of the brain that contain language. Aphasia causes problems with any or all of the following: speaking, listening, reading, and writing.

Damage to the left side of the brain causes aphasia for most right-handers and about half of left-handers. Individuals who experience damage to the right side of the brain may have additional difficulties beyond speech and language.

Individuals with aphasia may also have other problems, such as dysarthria, apraxia, or swallowing problems.

What are some signs or symptoms of aphasia?

Some people with aphasia have trouble using words and sentences (expressive aphasia). Some have problems understanding others (receptive aphasia). Others with aphasia struggle with both using words and understanding (global aphasia).

Aphasia can cause problems with spoken language (talking and understanding) and written language (reading and writing). Typically, reading and writing are more impaired than talking or understanding.

Aphasia may be mild or severe. The severity of communication difficulties depends on the amount and location of the damage to the brain.

A Person With Mild Aphasia

  • may be able to carry on normal conversations in many settings
  • may have trouble understanding language when it is long and/or complex
  • may have trouble finding the words (called anomia) to express an idea or explain himself/herself-this is like having a word "on the tip of your tongue"

A Person With Severe Aphasia

  • may not understand anything that is said to him/her
  • may say little or nothing at all
  • may make approximations of common phrases, such as "yes," "no," "hi," and "thanks"

Characteristics of Expressive Aphasia

  • Speaks only in single words (e.g., names of objects)
  • Speaks in short, fragmented phrases
  • Omits smaller words like "the," "of," and "and" (so message sounds like a telegram)
  • Puts words in wrong order
  • Switches sounds and/or words (e.g., bed is called table or dishwasher a "wish dasher")
  • Makes up words (e.g., jargon)
  • Strings together nonsense words and real words fluently but makes no sense

Characteristics of Receptive Aphasia

  • Requires extra time to understand spoken messages (e.g., like translating a foreign language)
  • Finds if very hard to follow fast speech (e.g., radio or television news)
  • Misinterprets subtleties of language-takes the literal meaning of figurative speech (e.g., "it's raining cats and dogs")
  • Is frustrating for the person with aphasia and for the listener—can lead to communication breakdown

Very often, a person with aphasia has both expressive and receptive difficulties to varying degrees.

How is aphasia diagnosed?

The speech-language pathologist (SLP) works collaboratively with the person's family and other professionals (doctors, nurses, neuropsychologists, occupational therapists, physical therapists, social workers) to address all of the person's needs. For example, a person who has had a stroke often has physical problems, such as weakness on one side of the body, that require treatment from a physical or occupational therapist.

The SLP evaluates the individual and determines the type and severity of aphasia. The evaluation is done by assessing the following areas of communication:


  • Fluency, vocal quality, and loudness
  • How clearly the person speaks
  • Strength and coordination of the speech muscles (tongue, lips)


  • Understanding and use of vocabulary (semantics) and grammar (syntax)
  • Understanding and answering both yes-no (e.g., Is your name Bob?) and Wh-questions (e.g., What do you do with a hammer?)
  • Understanding extended speech-the person listens to a short story or factual passage and answers fact-based (the answers are in the passage) and inferential (the patient must arrive at a conclusion based on information gathered from the reading) questions about the material
  • Ability to follow directions that increase in both length and complexity
  • Ability to tell an extended story (language sample) both verbally and in written form


  • Can the person tell the steps needed to complete a task or can he or she tell a story, centering on a topic and chaining a sequence of events together?
  • Can he or she describe the "plot" in an action picture?
  • Is his or her narrative coherent or is it difficult to follow?
  • Can the person recall the words he or she needs to express ideas?
  • Is the person expressing himself or herself in complete sentences, telegraphic sentences or phrases, or single words?

Social Communication

  • Social communication skills (pragmatic language)
  • Ability to interpret or explain jokes, sarcastic comments, absurdities in stories or pictures (e.g., What is strange about a person using an umbrella on a sunny day?)
  • Ability to initiate conversation, take turns during a discussion, and express thoughts clearly using a variety of words and sentences
  • Ability to clarify or restate when his or her conversational partner does not understand

Reading and Writing

  • Reading and writing of letters, words, phrases, sentences, and paragraphs


This information is gathered through both structured observations and formal tests.

What treatments are available for people with aphasia?

There are many types of treatment available for individuals with aphasia. The type of treatment depends on the needs and goals of the person with aphasia. There are specialized programs using computers or other published materials. There are also less formal approaches available. For many, a combination of formal and informal tasks is most appropriate. One approach that is used by some SLPs is the life participation approach to the treatment of aphasia. This is not the only treatment available, however.

What other organizations have information about aphasia?

This list is not exhaustive and inclusion does not imply endorsement of the organization or the content of the Web site by ASHA.

What causes aphasia?

Aphasia is most often caused by stroke. Any disease or damage to the parts of the brain that control language can cause aphasia. These include traumatic brain injury, dementia, illness, and other progressive neurological disorders.

How effective are treatments for aphasia?

ASHA produced a treatment efficacy summary on aphasia [PDF] that describes evidence about how well treatment works. This summary is useful not only to individuals with aphasia and caregivers but also to insurance companies considering payment for much needed services for aphasia.

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What does a speech-language pathologist do when working with individuals with aphasia?

The speech-language pathologist (SLP) works on drills and exercises to improve specific language skills affected by damage to the brain. For example, the person may practice naming objects, following directions, or answering questions about stories. These exercises vary depending on individual needs and become more complex and challenging as skills improve.

The SLP also teaches the person ways to make use of stronger language skills. For example, some people may find it easier to express their ideas through gestures and writing than with speaking. The SLP may teach this person to use both writing and gestures to help remember words for conversation.

The person may participate in group therapy sessions to practice conversational skills with other persons with aphasia. The SLP may lead the group through structured discussions, focusing on improving initiation of conversation, turn-taking, and repairing conversational breakdowns. Group members may role-play common communication situations that take place in the community and at home, such as talking on the telephone, ordering a meal in a restaurant, and talking to a salesperson at a store.

Eventually, individuals may participate in outings to practice communicating in real-life situations. They may be asked to plan, organize, and carry out these trips using the compensatory strategies they have learned. For example, group members may practice functional reading and writing skills by using a telephone book to find the phone number of a restaurant and write it down. They may practice telephone skills by calling the restaurant and making a reservation. They may practice reading maps, taking public transportation to the restaurant, counting the change needed to purchase a ticket, and ordering food.

Later on in recovery, the SLP may work with a vocational specialist to help the person return to work or school, if appropriate. The SLP works with employers and/or educational specialists to implement the use of compensatory strategies in these settings and may work with them to modify the environment to meet language needs.

The Academy of Neurologic Communication Disorders & Sciences (ANCDS) has published practice guidelines for aphasia.

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