Aphasia is a neurological disorder caused by damage to the parts of the brain that control language.


Aphasia is not a disease, but a symptom of brain damage. Aphasia is commonly seen in adults who have suffered a stroke. Aphasia also can result from:

  • A brain tumor.

  • Infection.

  • Head injury.

  • A rare type of dementia called Primary Progressive Aphasia. Common types of dementia may be associated with aphasia but can also exist without language problems.


Primary signs of the disorder include:

  • Problems expressing oneself when speaking.

  • Trouble understanding speech.

  • Difficulty with reading and writing.

  • Speaking in short or incomplete sentences.

  • Speaking in sentences that don't make sense.

  • Speaking unrecognizable words.

  • Interpreting figurative language literally.

  • Writing sentences that don't make sense.

The type and severity of language problems depend on the precise location and extent of the damaged brain tissue.

Aphasia can be divided into four broad categories:

  • Expressive aphasia - difficulty in conveying thoughts through speech or writing. The patient knows what they want to say, but cannot find the words they need.

  • Receptive aphasia - difficulty understanding spoken or written language. The patient hears the voice or sees the print but cannot make sense of the words.

  • Anomic or amnesia aphasia - difficulty in using the correct names for particular objects, people, places, or events. This is the least severe form of aphasia.

  • Global aphasia results from severe and extensive damage to the language areas of the brain. Patients lose almost all language function, both comprehension (understanding) and expression. They cannot speak, understand speech, read, or write.


Sometimes an individual will completely recover from aphasia without treatment. In most cases, language therapy should begin as soon as possible. Language therapy should be tailored to the individual needs of the patient. Therapy with a speech pathologist involves exercises in which patients:

  • Read.

  • Write.

  • Follow directions.

  • Repeat what they hear.

  • Computer-aided therapy may also be used.


The outcome of aphasia is difficult to predict. People who are younger or have less extensive brain damage do better. The location of the injury is also important. The location is a clue to prognosis. In general, patients tend to recover skills in language comprehension (understanding) more completely than those skills involving expression (speaking or writing).