Health Library


What is aphasia?

Aphasia is a language disorder caused by damage in a specific area of the brain that controls language expression and comprehension. Aphasia leaves a person unable to communicate effectively with others.

Many people have aphasia as a result of stroke. Both men and women are affected equally, and most people with aphasia are in middle to old age.

There are many types of aphasia, which are usually diagnosed based on which area of the language-dominant side of the brain is affected and the extent of the damage. For example:

  • People with Broca's aphasia have damage to the front portion of the language-dominant side of the brain.
  • Those with Wernicke's aphasia have damage to the side portion of the language-dominant part of the brain.

Global aphasia is the result of damage to a large portion of the language-dominant side of the brain.


What causes aphasia?

Aphasia is caused by damage to the language-dominant side of the brain, usually the left side, and may be brought on by:

  • Stroke
  • Head injury
  • Brain tumor
  • Infection
  • Dementia

It is currently unknown if aphasia causes the complete loss of language structure, or if it causes difficulties in how language is accessed and used.

What are the symptoms of aphasia?

The symptoms of aphasia depend on which type a person has.

People with Broca's aphasia, sometimes called an expressive aphasia, for example, may eliminate the words "and" and "the" from their language, and speak in short, but meaningful, sentences. They usually can understand some speech of others. Because the damage is in the front part of the brain, is also important for motor movements, people with Broca's aphasia often have right-sided weakness or paralysis of the arm and leg.

Those with Wernicke's aphasia, sometimes called a receptive aphasia, may speak in long confusing sentences, add unnecessary words, or create new words. They usually have difficulty understanding the speech of others.

People with global aphasia have difficulties with speaking or comprehending language.

How is aphasia diagnosed?

Confirmation of aphasia, extent of the disorder, and prediction for successful treatment may be assessed and confirmed by a set of comprehensive language tests conducted by a speech-language pathologist. These tests include studying speech, naming, repetition, comprehension, reading, and writing. Making a diagnosis may also include the use of imaging procedures to look at the brain, such as:

  • Computed tomography (CT). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images (often called slices) of the body. CT scans are more detailed than general X-rays.
  • Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body.
  • Positron emission tomography (PET). A computer-based imaging technique that uses radioactive substances to examine body processes.


How is aphasia treated?

Specific treatment for aphasia will be determined by your health care provider based on:

  • Your age, overall health, and medical history
  • The cause and extent of the disorder
  • Your handedness (left handed or right handed)
  • Your tolerance for specific medications, procedures, or therapies
  • Expectations for the course of the disorder
  • Your opinion or preference and motivation

The goal of treatment is to improve your ability to communicate through methods that may include:

  • Speech-language therapy
  • Nonverbal communication therapies, such as computers or pictures
  • Group therapy for patients and their families

Living with aphasia

Some people with aphasia recover completely without treatment. But for most people, some amount of aphasia typically remains. Treatments such as speech therapy can often help recover some speech and language functions over time, but many people continue to have problems communicating. This can sometimes be difficult and frustrating both for the person with aphasia and for family members. It's important for family members to learn the best ways to communicate with their loved one. Speech therapists can often help with this. Suggestions might include the following:


  • Include the person with aphasia in conversations 
  • Simplify language by using short, simple sentences
  • Repeat key words or write them down to clarify meaning as needed
  • Use a natural conversational manner at an adult level
  • Encourage all types of communication, including speech, gestures, pointing, or drawing
  • Don’t correct the person's speech
  • Give the person plenty of time to express themselves
  • Help the person become involved outside the home, such as through support groups

For some people, computers can be helpful for both communicating and improving language abilities.

Key points

  • Aphasia is a language disorder caused by damage to parts of the brain that control speech and understanding of language.
  • Depending on which areas of the brain are affected, a person might have different levels of ability to speak and understand others.
  • Aphasia might get better over time, but many people are left with some loss of language skills. Speech therapy can often be helpful, as can other tools such as computers that can help people communicate.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.

  • Bookmark
  • Print

    Find a Doctor

Click the button above or call
1 877 NYP WELL

Top of page