Aphasia is a communication disorder that occurs due to brain damage in one or more areas that control language. It can interfere with your verbal communication, written communication, or both. It can cause problems with your ability to:

  • read
  • write
  • speak
  • understand speech
  • listen

According to the National Aphasia Association, about 1 million Americans have some form of aphasia.

Symptoms of aphasia vary from mild to severe. They depend on where the damage occurs in your brain and the severity of that damage.

Aphasia can affect your:

  • speaking
  • comprehension
  • reading
  • writing
  • expressive communication, which involves using words and sentences
  • receptive communication, which involves understanding the words of others

Symptoms that affect expressive communication can include:

  • speaking in short, incomplete sentences or phrases
  • speaking in sentences that other can’t understand
  • using the wrong words or nonsense words
  • using words in the wrong order

Symptoms that affect receptive communication can include:

  • difficulty understanding other people’s speech
  • difficulty following fast-paced speech
  • misunderstanding figurative speech

The four major types of aphasia are:

  • fluent
  • nonfluent
  • conduction
  • global

Fluent aphasia

Fluent aphasia is also called Wernicke’s aphasia. It typically involves damage to the middle left side of your brain. If you have this type of aphasia, you can speak but you have trouble understanding when others speak. If you have fluent aphasia, it’s likely you’ll:

  • be unable to understand and use language correctly
  • tend to speak in long, complex sentences that are meaningless and include incorrect or nonsense words
  • not realize that others can’t understand you

Nonfluent aphasia

Nonfluent aphasia is also called Broca’s aphasia. It typically involves damage to the left frontal area of your brain. If you have nonfluent aphasia, you’ll likely:

  • speak in short, incomplete sentences
  • be able to convey basic messages, but you may be missing some words
  • have a limited ability to understand what others say
  • experience frustration because you realize that others can’t understand you
  • have weakness or paralysis on the right side of your body

Conduction aphasia

Conduction aphasia typically involves trouble repeating certain words or phrases. If you have this type of aphasia, you’ll likely understand when others are talking. It’s also likely that others will understand your speech but you may have trouble repeating words and make some mistakes when speaking.

Global aphasia

Global aphasia typically involves major damage to the front and back of the left side of your brain. If you have this type of aphasia, you’ll likely:

  • have severe problems using words
  • have severe problems understanding words
  • have limited ability to use a few words together

Aphasia occurs due to damage to one or more areas of your brain that control language. When damage occurs, it can interrupt the blood supply to these areas. Without oxygen and nutrients from your blood supply, the cells in these parts of your brain die.

Aphasia can occur due to:

  • a brain tumor
  • an infection
  • dementia or another neurological disorder
  • a degenerative disease
  • a head injury
  • a stroke

Strokes are the most common cause of aphasia. According to the National Aphasia Association, aphasia occurs in 25 to 40 percent of people who’ve had a stroke.

Causes of temporary aphasia

Seizures or migraines can cause temporary aphasia. Temporary aphasia can also occur due to a transient ischemic attack (TIA), which temporarily interrupts blood flow to your brain. A TIA is often called a ministroke. The effects of a TIA include:

  • weakness
  • numbness of certain body parts
  • difficulty speaking
  • difficulty understanding speech

A TIA is different from a stroke because its effects are temporary.

Aphasia affects people of all ages, including children. Since strokes are the most common cause of aphasia, the majority of people with aphasia are middle-aged or older.

If your doctor suspects you have aphasia, they may order imaging tests to find the source of the problem. A CT or MRI scan can help them identify the location and severity of your brain damage.

You doctor may also screen you for aphasia during treatment for a brain injury or stroke. For example, they may test your ability to:

  • follow commands
  • name objects
  • participate in a conversation
  • answer questions
  • write words

If you have aphasia, a speech-language pathologist can help identify your specific communication disabilities. During your examination, they’ll test your ability to:

  • speak clearly
  • express ideas coherently
  • interact with others
  • read
  • write
  • understand verbal and written language
  • use alternative forms of communication
  • swallow

Your doctor will recommend speech-language therapy to treat aphasia. This therapy typically proceeds slowly and gradually. You should start it as early as possible after a brain injury. Your specific treatment plan may involve:

  • performing exercises to improve your communication skills
  • working in groups to practice your communication skills
  • testing your communication skills in real-life situations
  • learning to use other forms of communication, such as gestures, drawings, and computer-mediated communication
  • using computers to relearn word sounds and verbs
  • encouraging family involvement to help you communicate at home

If you have temporary aphasia due to a TIA or a migraine, you may not need treatment. If you have another type of aphasia, you’ll likely recover some language abilities up to a month after you sustain brain damage. However, it’s unlikely that your full communication abilities will return.

Several factors determine your outlook:

  • the cause of the brain damage
  • the location of the brain damage
  • the severity of the brain damage
  • your age
  • your overall health
  • your motivation to follow your treatment plan

Talk to your doctor to get more information about your specific condition and long-term outlook.

Many of the conditions that cause aphasia aren’t preventable, such as brain tumors or degenerative diseases. However, the most common cause of aphasia is stroke. If you reduce your risk of stroke, you can lower your risk of aphasia.

Take the following steps to lower your risk of stroke:

  • Stop smoking if you smoke.
  • Drink alcohol only in moderation.
  • Exercise daily.
  • Eat a diet that’s low in sodium and fat.
  • Take steps to control your blood pressure and cholesterol.
  • Take steps to control diabetes or circulation problems if you have them.
  • Get treatment for atrial fibrillation if you have it.
  • Get immediate medical care if you develop the symptoms of a stroke.

Read more: Stroke symptoms »