What is aphasia?

Aphasia is a disorder that results from damage to areas of the brain that produce and process language. A person with aphasia can have trouble speaking, reading, writing, and understanding language. Impairment in these abilities can range from mild to very severe (nearly impossible to communicate in any form). Some people with aphasia have difficulty in only one area of communication, such as trouble putting words together into meaningful sentences, trouble reading, or difficulty understanding what others are saying. More commonly, people with aphasia are limited in more than one communication area. Nearly all patients with aphasia have word-finding difficulties – that is, coming up with the correct name of persons, places, things, or events.

Each person’s experience with aphasia is unique. It depends on the location(s) of the stroke or brain injury that has caused the aphasia, extent of damage, age of the person, general health of the person and ability to recover.

Are there different types of aphasia?

Yes. There are many types of aphasia. In addition, there are several ways to categorize the different types of aphasia.

One common way categorizes aphasia based on three factors:

  • Speech fluency: Can the person speak with ease and in sentences (fluent) or can they only speak a few words at a time and with great effort (non-fluent)?
  • Language comprehension: Does the person have good or poor understanding of spoken or written words?
  • Ability to repeat: Can the person repeat words and phrases?

Many clinicians also broadly define aphasia by expressive or receptive types:

  • Expressive: How much trouble does the person have expressing thoughts and ideas through speech or writing?
  • Receptive: How much trouble does the person have understanding spoken language or reading?

Who is at risk for aphasia?

Aphasia can happen to anyone, regardless of age; however, it is more common in those who are middle-aged and older. In the Unites States, approximately 1 million people have aphasia, according to the National Aphasia Association. In addition, about 180,000 people are diagnosed with aphasia each year.

What causes aphasia?

Aphasia results from damage to one or more of the areas of the brain responsible for language. Aphasia can occur suddenly, such as after a stroke (most common cause) or head injury or brain surgery, or may develop more slowly, as the result of a brain tumor, brain infection or neurological disorder such as dementia.

Related issues. Brain damage can also result in other problems that affect speech. These problems include dysarthrias (weakness or lack of control in the muscles of the face or mouth resulting in slowed or slurred speech), apraxia (inability to move lips or tongue in the right way to say sounds) and dysphagia (swallowing problems).

What are the signs and symptoms of aphasia?

Signs and symptoms of aphasia vary depending on the portion of the brain affected, extent of the area affected and type of aphasia. Possible symptoms include:

  • Trouble naming objects, places, events or people even though they are known to the person (“tip of the tongue” phenomenon)
  • Trouble expressing oneself (finding the right words) when speaking or writing
  • Trouble understanding conversation
  • Trouble reading
  • Trouble spelling
  • Leaving out small words like “the,” “of” and “was” from speech
  • Putting words in the wrong order
  • Being unaware of mistakes in one’s spoken language
  • Speaking only in short phrases, which are produced with great effort
  • Speaking in single words
  • Making up words
  • Mixing up sounds in words (saying “wog dalker” for “dog walker”)
  • Saying the wrong word (saying “bird” instead of “dog”) or substituting a word that doesn’t make sense (saying “ball” for “phone”)
  • Speech limited to only a few words or repeating the same words or phrases over and over
  • Trouble putting words together to write sentences
  • Trouble using numbers or doing math

Last reviewed by a Cleveland Clinic medical professional on 07/09/2019.


  • National Institute on Deafness and Other Communication Disorders. National Institutes of Health. Aphasia. Accessed 6/4/2019.
  • National Institute of Neurological Disorders and Stroke. National Institutes of Health. Aphasia Information Page. Accessed 6/4/2019.
  • National Aphasia Association. Aphasia. Accessed 6/4/2019.
  • American Speech-Language Hearing Association. Aphasia. Accessed 6/4/2019.

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