What is aphasia?

Who has aphasia? 

What causes aphasia?

What types of aphasia are there?

Aphasia is a disorder that results from damage to 

portions of the brain that are responsible for language. 

For most people, these are areas on the left side 

(hemisphere) of the brain. Aphasia usually occurs 

suddenly, often as the result of a stroke or head injury, 

but it may also develop slowly, as in the case of a 

brain tumor, an infection, or dementia. The disorder 

impairs the expression and understanding of language 

as well as reading and writing. Aphasia may co-occur 

with speech disorders such as dysarthria or apraxia of 

speech, which also result from brain damage.

There are two broad categories of aphasia: fluent and 

non-fluent. 

Damage to the temporal lobe (the side portion) of the 

brain may result in a fluent aphasia called Wernicke’s 

aphasia (see figure). In most people, the damage 

occurs in the left temporal lobe, although it can result 

from damage to the right lobe as well. People with 

Wernicke’s aphasia may speak in long sentences that 

have no meaning, add unnecessary words, and even 

create made-up words. For example, someone with 

Wernicke’s aphasia may say, “You know that smoodle 

pinkered and that I want to get him round and take 

care of him like you want before.” As a result, it is 

often difficult to follow what the person is trying to 

say. People with Wernicke’s aphasia usually have great 

difficulty understanding speech, and they are often 

unaware of their mistakes. These individuals usually 

Anyone can acquire aphasia, including children, but 

most people who have aphasia are middle-aged or 

older. Men and women are equally affected. According 

to the National Aphasia Association, approximately 

80,000 individuals acquire aphasia each year from 

strokes. About one million people in the United States 

currently have aphasia. 

Aphasia is caused by damage to one or more of the 

language areas of the brain. Many times, the cause of 

the brain injury is a stroke. A stroke occurs when blood 

is unable to reach a part of the brain. Brain cells die 

when they do not receive their normal supply of blood, 

which carries oxygen and important nutrients. Other 

causes of brain injury are severe blows to the head, 

brain tumors, brain infections, and other conditions 

that affect the brain.

Areas of the brain affected by Broca’s and 

Wernicke’s aphasia

NIDCD Fact Sheet

Aphasia 

u.s. department of health & human services ∙ national institutes of health ∙ National Institute on Deafness and Other Communication Disorders voice, speech, language language
How is aphasia diagnosed?

How is aphasia treated?

have no body weakness because their brain injury is 

not near the parts of the brain that control movement. 

A type of non-fluent aphasia is Broca’s aphasia. People 

with Broca’s aphasia have damage to the frontal lobe 

of the brain. They frequently speak in short phrases 

that make sense but are produced with great effort. 

They often omit small words such as ”is,” ”and,” and 

”the.” For example, a person with Broca’s aphasia 

may say, ”Walk dog,” meaning, ”I will take the dog 

for a walk,” or ”book book two table,” for ”There 

are two books on the table.” People with Broca’s 

aphasia typically understand the speech of others fairly 

well. Because of this, they are often aware of their 

difficulties and can become easily frustrated. People 

with Broca’s aphasia often have right-sided weakness 

or paralysis of the arm and leg because the frontal lobe 

is also important for motor movements. 

Another type of non-fluent aphasia, global aphasia, 

results from damage to extensive portions of the 

language areas of the brain. Individuals with global 

aphasia have severe communication difficulties and 

may be extremely limited in their ability to speak or 

comprehend language.

There are other types of aphasia, each of which results 

from damage to different language areas in the brain. 

Some people may have difficulty repeating words 

and sentences even though they can speak and they 

understand the meaning of the word or sentence. 

Others may have difficulty naming objects even though 

they know what the object is and what it may be 

used for. 

Aphasia is usually first recognized by the physician 

who treats the person for his or her brain injury. 

In some cases, a person will completely recover from 

aphasia without treatment. This type of spontaneous 

recovery usually occurs following a type of stroke 

in which blood flow to the brain is temporarily 

interrupted but quickly restored, called a transient 

ischemic attack. In these circumstances, language 

abilities may return in a few hours or a few days. 

For most cases, however, language recovery is not as 

quick or as complete. While many people with aphasia 

experience partial spontaneous recovery, in which 

some language abilities return a few days to a month 

after the brain injury, some amount of aphasia typically 

remains. In these instances, speech-language therapy 

is often helpful. Recovery usually continues over a twoyear period. Many health professionals believe that the 

most effective treatment begins early in the recovery 

process. Some of the factors that influence the 

amount of improvement include the cause of the brain 

damage, the area of the brain that was damaged, the 

extent of the brain injury, and the age and health of 

the individual. Additional factors include motivation, 

handedness, and educational level. 

Frequently this is a neurologist. The physician typically 

performs tests that require the person to follow 

commands, answer questions, name objects, and 

carry on a conversation. If the physician suspects 

aphasia, the patient is often referred to a speechlanguage pathologist, who performs a comprehensive 

examination of the person’s communication abilities. 

The examination includes the person’s ability to speak, 

express ideas, converse socially, understand language, 

read, and write, as well as the ability to swallow and to 

use alternative and augmentative communication.

NIDCD Fact Sheet

Aphasia

voice, speechlanguage
What research is being done for aphasia?

Aphasia therapy aims to improve a person’s ability to 

communicate by helping him or her to use remaining 

language abilities, restore language abilities as much 

as possible, compensate for language problems, and 

learn other methods of communicating. Individual 

therapy focuses on the specific needs of the person, 

while group therapy offers the opportunity to use new 

communication skills in a small-group setting. Stroke 

clubs, regional support groups formed by people who 

have had a stroke, are available in most major cities. 

These clubs also offer the opportunity for people with 

aphasia to try new communication skills. In addition, 

stroke clubs can help a person and his or her family 

adjust to the life changes that accompany stroke 

and aphasia.

Family involvement is often a crucial component of 

aphasia treatment so that family members can learn 

the best way to communicate with their loved one. 

Family members are encouraged to:

•	 Simplify language by using short, uncomplicated 

sentences. 

•	 Repeat the content words or write down key 

words to clarify meaning as needed. 

•	 Maintain a natural conversational manner 

appropriate for an adult. 

•	 Minimize distractions, such as a loud radio or TV, 

whenever possible. 

•	 Include the person with aphasia in conversations. 

•	 Ask for and value the opinion of the person with 

aphasia, especially regarding family matters. 

•	 Encourage any type of communication, whether it 

is speech, gesture, pointing, or drawing. 

Scientists are attempting to reveal the underlying 

problems that cause certain symptoms of aphasia. The 

goal is to understand how injury to a particular part 

of the brain impairs a person’s ability to convey and 

understand language. The results could be useful in 

treating various types of aphasia, since the treatment 

may change depending upon the cause of the 

language problem. 

Other research is attempting to understand the parts 

of the language process that contribute to sentence 

comprehension and production and how these parts 

may break down in aphasia. In this way, it may be 

possible to pinpoint where the breakdown occurs and 

help in the development of more focused treatment 

programs.

•	 Avoid correcting the person’s speech. 

•	 Allow the person plenty of time to talk. 

•	 Help the person become involved outside 

the home. Seek out support groups such as 

stroke clubs. 

Other treatment approaches involve the use of 

computers to improve the language abilities of people 

with aphasia. Studies have shown that computerassisted therapy can help people with aphasia retrieve 

certain parts of speech, such as the use of verbs. 

Computers can also provide an alternative system of 

communication for people with difficulty expressing 

language. Lastly, computers can help people who 

have problems perceiving the difference between 

phonemes (the sounds from which words are formed) 

by providing auditory discrimination exercises.

more
Where can I get additional information?

NIDCD maintains a directory of organizations that can 

answer questions and provide printed or electronic 

information on aphasia. Please see the list of 

organizations at http://www.nidcd.nih.gov/directory.

Use the following subject areas to help you search for 

organizations that are relevant to aphasia:

•	 Aphasia

•	 Speech-language pathologists

•	 Augmentative and alternative communication

Although different languages have many things in 

common when specific portions of the brain are 

injured, there are also differences. Scientists are trying 

to understand the common (or universal) symptoms 

of aphasia and the language-specific symptoms of the 

disorder. Other researchers are examining whether 

people with aphasia may still know their language 

but have difficulty accessing that knowledge. These 

studies may help with the development of tests 

and rehabilitation strategies that focus on specific 

characteristics of one language or multiple languages.

Researchers are exploring drug therapy as an 

experimental approach to treating aphasia. Some 

studies are testing how drugs can be used in 

combination with speech therapy to improve recovery 

of various language functions. 

Researchers are also looking at how treatment of other 

cognitive deficits involving attention and memory can 

improve communication abilities.

To understand recovery processes in the brain, some 

researchers are using functional magnetic resonance 

imaging (fMRI) to better understand the human 

brain regions involved in speaking and understanding 

language. This type of research may improve 

understanding of how these areas reorganize after 

brain injury. The results could have implications for 

both the basic understanding of brain function and the 

diagnosis and treatment of neurological diseases.

For more information, additional addresses and phone 

numbers, or a printed list of organizations, contact:

NIDCD Information Clearinghouse

1 Communication Avenue 

Bethesda, MD 20892-3456

Toll-free Voice: (800) 241-1044

Toll-free TTY: (800) 241-1055

E-mail: nidcdinfo@nidcd.nih.gov

NIDCD supports and conducts research and research training on the 

normal and disordered processes of hearing, balance, smell, taste, 

voice, speech, and language and provides health information, based 

upon scientific discovery, to the public.

voice, speech, languagehearing, balancesmell, taste

NIDCD Fact Sheet: Aphasia

Publication No. 08-4232

Updated October 2008

For more information, contact:

NIDCD Information Clearinghouse

1 Communication Avenue

Bethesda, MD 20892-3456

Toll-free Voice: (800) 241-1044

Toll-free TTY: (800) 241-1055

Fax: (301) 770-8977

E-mail: nidcdinfo@nidcd.nih.gov

Internet: http://www.nidcd.nih.gov

The NIDCD Information Clearinghouse is a service of the 

National Institute on Deafness and Other Communication 

Disorders, National Institutes of Health, U.S. Department 

of Health and Human Services.