What Is Aphasia?

Medically Reviewed by Zilpah Sheikh, MD on April 23, 2024
13 min read

Aphasia is a communication disorder that makes it hard to use words. It can affect your speech, writing, and ability to understand language. Aphasia results from damage or injury to parts of the brain that control language. It's more common in older adults, particularly those who've had a stroke.

Aphasia affects a person's ability to communicate, but it doesn’t impair intelligence. People who have aphasia may have a hard time speaking and finding the "right" words to complete their thoughts. They may also have problems understanding conversation, reading and comprehending written words, writing words, and using numbers. People with aphasia may also repeat words or phrases. 

The main symptoms of aphasia include:

  • Trouble speaking
  • Struggling with finding the right term or word
  • Using strange or wrong words in conversation
  • Trouble understanding what other people say or following conversations
  • Writing sentences that don’t make sense or trouble expressing yourself in writing
  • Speaking in short sentences or phrases
  • Using unrecognizable words

Aphasia may be mild or severe. With mild aphasia, you may be able to converse yet have trouble finding the right word or understanding complex conversations. Serious aphasia makes you less able to communicate. You may say little and may not take part in or understand any conversation. 

Some people with aphasia have problems understanding what others are saying. The problems occur particularly when you're tired or in a crowded or loud environment. Aphasia does not affect thinking skills. But you may have problems understanding written material and a hard time with handwriting. Some people have trouble using numbers or even doing simple calculations.

There are different types of aphasia. Each can cause language issues that range from mild to serious. But the verbal expressions can mostly be categorized as fluent or nonfluent aphasia.

Fluent vs. nonfluent aphasia

When you have fluent aphasia, you may be able to produce speech that contains connected sentences. But the sentences, while linked, may lack proper meaning. With nonfluent aphasia, your speech may have halts. You may need a lot of effort to string a sentence together, and it may not be grammatically correct. But you may still be able to preserve the meaning of the words enough to get the point across.

Expressive aphasia (Broca’s aphasia)

If you have this, you know what you want to say, but you’ll have a hard time communicating it to others. It doesn't matter whether you’re trying to speak or write what you’re trying to communicate.

Anomic aphasia

With anomic aphasia, you have a hard time finding words. This is called anomia. Because of the difficulties, you may struggle to find the right words for speaking and writing.

Wernicke’s aphasia

It’s also known as receptive aphasia. You can hear a voice or read print but may not understand the meaning of the message. Often, someone with receptive aphasia takes language literally. Their own speech may be disturbed because they do not understand their own language.

Conduction aphasia

This is also called associative aphasia. It’s a form where you may have trouble finding words or repeating phrases.

Transcortical motor aphasia

You may have strong repetition skills, but you may find it hard to answer questions without having to give them a lot of thought.

Sensory aphasia

With this type, you’re fairly good at repeating words and phrases. But you’re more likely to repeat questions that someone may ask you rather than answer them. This phenomenon is called echolalia.

Primary progressive aphasia

Primary progressive aphasia is a type of dementia. It’s a rare disorder where people slowly lose their ability to talk, read, write, and comprehend what they hear in conversation over a period of time. There’s no treatment to reverse primary progressive aphasia. People with primary progressive aphasia are able to communicate in ways other than speech. For instance, they might use gestures. And many benefit from a combination of speech therapy and medications.

Global aphasia

This is the most severe type of aphasia. It is often seen right after someone has a stroke. With global aphasia, you have a hard time speaking and understanding words. You also can’t read or write. With a stroke, aphasia may improve with proper therapy.

Other aphasia types 

These types usually don’t fit well under fluent or nonfluent aphasia. They can include:

  • Crossed aphasia. You may get this type of aphasia after you have an injury to the brain that controls the dominant side of your body. But it happens on the opposite side. For example, if you’re right-handed, usually the left hemisphere of your brain is dominant. But in this case, a stroke in the right hemisphere causes language problems in right-handed people.

  • Subcortical aphasia. This type of aphasia may develop if you’ve injured the subcortical region of the brain.  

Aphasia is usually caused by a stroke or brain injury with damage to one or more parts of the brain that deal with language. According to the National Aphasia Association, about one-third of people who survive a stroke get aphasia. A stroke happens when a blood clot or a leaking or burst vessel cuts off blood flow to part of your brain, causing brain cells to die.

Besides a stroke, other causes include:

  • Head injury
  • Brain tumor
  • Infection
  • Dementia

In some cases, aphasia is a symptom of epilepsy or another neurological disorder. As of today, experts aren’t sure if aphasia can cause you to completely lose language structure, or if it only affects your ability to access language and use it.

Sometimes aphasia happens in temporary episodes because of:

  • Migraine
  • Transient ischemic attack (TIA), when blood flow is temporarily blocked to an area of the brain



Frontotemporal dementia is the term doctors use to refer to a cluster of disorders that involve damage to cells in the frontal or temporal lobes of the brain. These are the parts of the brain involved in speech and language. 

Aphasia, specifically primary progressive aphasia, is a type of frontotemporal dementia. 

Usually, a doctor diagnoses aphasia when treating you for a stroke, brain injury, or tumor. Using a series of neurological tests, the doctor may ask you questions. The doctor may also issue specific commands and ask you to name items or objects. The results of these tests help the doctor determine if you have aphasia. They also help find out how severe the aphasia is.

Imaging tests used to diagnose aphasia include:

  • Computed tomography (CT) scan that uses X-rays and computers to make detailed images of the inside of your body
  • Magnetic resonance imaging (MRI), which uses large magnets, radio frequencies, and a computer to produce detailed images of organs and structures in your body
  • Positron emission tomography (PET) scan that uses radioactive substances to capture images of certain body processes 

If the doctor suspects aphasia, they may also refer you to a speech-language pathologist for a detailed exam. These medical professionals are trained to identify and improve language and communications skills.

During the exam, they may test to observe language skills such as:

  • Grammar
  • Ability to form sounds and letters
  • Ability to understand words and sentences
  • Object knowledge
  • Describing pictures
  • Using single words to name objects and pictures
  • Matching spoken words to pictures
  • Answering yes-or-no questions
  • Following directions

Aphasia vs. dysphasia

Aphasia is used to describe the total loss of language and speech from a brain injury. Dysphasia refers to the partial loss of language. But the term “aphasia” is usually used to refer to both conditions.

Aphasia vs. dysarthria

Unlike aphasia that happens because of a brain injury, dysarthria is a speech disorder. It may happen if the muscles used to speak become weak, injured, or paralyzed. Causes can include damage to the nervous system or neuromuscular conditions like amyotrophic lateral sclerosis (ALS; formerly known as Lou Gehrig’s disease), cerebral palsy, or multiple sclerosis.

Treatment for someone with aphasia depends on things such as:

  • Age
  • Cause of brain injury
  • Type of aphasia
  • Position and size of the brain lesion

For instance, a person with aphasia may have a brain tumor that's affecting the language center of the brain. Surgery to treat the brain tumor may also improve the aphasia.

Some tips from the National Stroke Association for someone with aphasia include:

  • Use props to help get the message across.
  • Draw words or pictures on paper when trying to communicate.
  • Speak slowly, and stay calm when talking.
  • Carry a card to let strangers know you have aphasia and what aphasia means.

Speech and language therapy. If you have aphasia and have had a stroke, you may benefit from sessions with a speech-language pathologist. It’s best to start as early as possible. The therapist will meet regularly with you to help you speak and communicate better. The therapist will also teach you ways to communicate that don't involve speech. This will help you compensate for language problems.

This type of therapy may also be done in group settings to start and practice conversations. The interaction may also help you relearn and correct mispronunciations. Therapy may also involve computer and tech devices to relearn words and phrases.

Nonverbal communication therapies. If aphasia limits how well you communicate properly using words and phrases, you may benefit from nonverbal communication therapy.

Your treatment plan may include:

  • A picture-based communication system
  • Using a communication book to draw
  • A drawing program
  • Working on using gestures
  • Working directly to improve function in areas that affect verbal communication

Medication. Certain drugs may help improve blood flow to the brain that can help it recover or replace some of the chemicals that may have been reduced after aphasia. Drugs like memantine (Namenda) and piracetam have shown some success in small studies. But more research needs to be done before they can be recommended for treatment.

Group therapy. This can be helpful for both someone affected by aphasia and their loved one. Licensed professionals can help you build tools to communicate well and adjust expectations through the recovery process.

Other treatments. Experts are studying brain stimulation treatments like transcranial magnetic stimulation and transcranial direct current stimulation. These are noninvasive options that stimulate damaged brain cells. But more research needs to be done.

The outlook for people with aphasia may depend on several things, such as:

  • Cause of brain injury
  • Extent of injury
  • Area of injury
  • Age
  • Health

If a stroke caused your aphasia, you’re likely to recover language skills within hours or days. For others, language problems may be a lifelong issue. And the aphasia may range from mild to severe.

If a neurodegenerative condition like dementia was the cause of aphasia, you may lose language skills over time.

Possible complications depend on the cause of the aphasia. This may include:

  • Depression
  • Loss of mobility
  • Loss of bladder or bowel control
  • Higher risk of infection
  • Pressure ulcers
  • Untreated pain


If you have aphasia, there are things you can do to improve your communication with others. You can:

  • Make gestures with your hands.
  • Use facial expressions.
  • Try using devices like a phone, computer, or communication apps for a video call.
  • Use communication aids like pictures.
  • Pantomime or act it out.
  • Combine reading, writing, and speaking to drive the point home.
  • Point to keywords.


If someone you know has aphasia, these tips can help you communicate better:

  • Get their attention before you say something.
  • Keep eye contact.
  • Pay attention to their body language.
  • Talk where it’s quiet.
  • Use simple words, but don’t use childish language.
  • Use shorter sentences and repeat important words.
  • Talk slowly.
  • Give them time to say something.
  • Try drawings, gestures, writing, or facial expressions if words aren’t working.
  • Ask them to draw, write, or point if they are having trouble.
  • Ask yes-or-no questions.
  • Let them make mistakes and try.
  • Don’t talk louder. People with aphasia hear normally.
  • Don’t finish their thoughts for them.

Aphasia can often be a sign of a serious medical problem like a stroke. Tell your doctor right away If you notice that you suddenly have issues like:

  • A hard time speaking
  • Trouble understanding speech
  • Unable or finding it hard to recall words
  • Problems with reading or writing

If it’s a medical emergency, call 911 or head to the nearest hospital.

Feeling tired or stressed

Simply being tired or fatigued can make it hard to think of the right words. And when you're worried about being judged by others or feel embarrassed, you may freeze up or struggle to talk.

Anxiety, especially if it crops up when you're in front of a lot of people, can lead to dry mouth, stumbling over your words, and more troubles that can get in the way of speaking.

It's OK to be nervous. Don't worry so much about being perfect. Taking that pressure off of yourself might get your words flowing again.

Better self-care, therapy, and support groups may help when you're feeling wound up or worn out or have social anxiety. Depending on the situation, your doctor may be able to prescribe medication, too.

Too much to drink

Alcohol is widely known to cause slurred speech because it slows down how the brain communicates with the body. Your liver can only break down a little alcohol at a time, leaving the rest in your bloodstream. The more you drink, the more intense the effects and the longer they last.

If you're concerned about your drinking, ask your doctor for advice.


Trouble speaking, along with having a numb or drooping face and feeling weak in one arm or a leg, is one of the major warning signs of stroke. When the oxygen supply has been cut off to your brain by a blood clot or you have bleeding in the brain, you could have slurred speech, be hard to understand, or be unable to talk at all.

Permanent language problems, called aphasia, are often the result of a stroke.

Call 911 as soon as stroke symptoms appear so that trained emergency workers can get you to the right hospital quickly. Don't wait or try to get there on your own.

A severe migraine headache can also mess with your words. This is called transient aphasia because it will go away.

Migraines are known for being very painful and sometimes leading to changes in the senses, too. Up to one-fourth of people who have migraines say they get an aura ahead of time, where they see flashing lights or have blind spots. Other symptoms you could have during the migraine are numbness, dizziness, confusion, or trouble speaking. You can even feel these symptoms without having a painful headache.

The exact causes of migraine aren't fully clear, but some can be prevented by watching your diet and lifestyle, using prescription medications, and taking certain vitamins. Treatment for the headaches may include over-the-counter painkillers and nausea medicines as well as prescription drugs.

If you find migraines are getting in the way of your daily life, your regular doctor may refer you to a specialist called a neurologist.

Neurological conditions

Certain neurological conditions can affect your speech.

Multiple sclerosis. Multiple sclerosis (MS) is a disease that changes how the brain sends information between its cells and with the rest of the body. People with MS who have lesions in areas of the brain responsible for speech can have speech issues that range from mild to severe. A common pattern in MS is "scanning speech," which is when the rhythm of how you talk has extra-long pauses between words and syllables.

Weak muscles and trouble coordinating the muscles in your mouth and cheeks can make it hard for someone with MS to say words, too.

Brain cancer. Brain cancer, if the tumor is in the part of the brain that handles language, could also affect your speech. Other common symptoms of brain cancer are headaches, seizures, changes in personality or memory, nausea, unusual sleepiness, and struggling to do daily activities.

Seizures. One type of seizure, a sudden burst of brain activity that people with epilepsy have, affects specific muscles depending on where in the brain it happens. Another type can make people look awake but actually unaware of what's going on around them. They may also make strange noises, gag, or smack their lips and not realize they've done it. Seizures could be caused by strokes or brain tumors that affect the language zones, too.


A wide range of medications and supplements -- from allergy medications to blood pressure drugs and even high doses vitamin C -- can affect your voice by drying out the mucus that protects your vocal cords. They also can thin your blood, which means your vocal cords would be easier to injure. They can make your body retain fluid, which enlarges your vocal cords and could make you hoarse.

Some narcotics and sedatives can slow or slur speech by making it hard for you to control your mouth muscles.

Not being able to speak normally is a side effect of the antidepressant bupropion. Topiramate, a medicine for controlling seizures, might lead to speech problems like finding the right words, though these typically go away when your doctor lowers the dose or you stop taking the drug.

If you've just begun taking a new medicine, check its label, the package insert, or ask your pharmacist if that could be related to your speech problems. Learn more about common side effects of medications.

Aphasia is a disorder that happens when damage happens to the language and speech parts of your brain. It affects your ability to communicate, but not your intelligence. The way your communication is affected depends on the type of aphasia you have. Treatment for aphasia includes speech-language therapy, medication, other types of therapy, and brain stimulation.

  • Can a person with aphasia live alone? Your ability to live independently will depend on several factors, including the cause of your condition, age, and overall health. If your aphasia is the result of a stroke, there may be other symptoms that make living alone more difficult. 

  • Does aphasia turn into dementia? Not always. If you have primary progressive aphasia, you may gradually lose your ability to speak, write, read or understand what others are saying. But aphasia caused by injury or stroke doesn’t get worse over time.