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What is Aphasia?

Aphasia (pronounced Uh-FAY-zhuh) is a communication disorder caused by a stroke, brain injury, or, more rarely, a condition called Primary Progressive Aphasia (PPA). It affects a person’s ability to use language.  Therefore, a person may have challenges talking, understanding others, reading, writing, and using numbers.  Aphasia does not impact intelligence or memory, but is highly dependent on the cause, location, and extent of damage.  It is a frustrating impairment as people with aphasia still know what they want to say and can make their own decisions. Aphasia can range from mild to severe and may impact one or several aspects of communication.

Aphasia Statistics

2,000,000+
people in US alone have Aphasia

33%
have never heard the term "Aphasia"

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How We Talk About "Types" of Aphasia

Over more than a century of studying aphasia, experts have learned that language abilities can be affected in different ways depending on the location of the brain injury. These patterns are often grouped into “types” of aphasia.  Each “type” has particular language strengths and challenges and can be further complicated by the presence of a motor speech disorder, a cognitive component, etc. However, it’s important to remember that a person’s aphasia can change over time and with rehabilitation efforts. Being described as a certain type early on doesn’t mean you will always fit neatly into that category.

Fluent and Nonfluent Categories of Aphasia

Fluent and Nonfluent Categories of Aphasia

In this diagram, you will note that the types of aphasia are further broken into “fluent” and “nonfluent” categories.  A person with Fluent Aphasia may have speech that sounds smooth with natural rhythm and intonation, but words that may not make sense.  This is challenging, as this individual could be using long sentences and not realize that they are not making sense.  Comprehension is the real struggle with fluent aphasias.  A person with Nonfluent Aphasia may struggle to form complete sentences, leave out small words, and mix up terms for people or items. Their speech can be hesitant and effortful.  Because they generally have a better understanding, however, they can become more frustrated as they know they are not getting the words out that they intend.

We understand that many of these terms will be new to you as you begin an aphasia journey, so we have compiled a glossary with information that is both informative and accessible.

Causes of Aphasia

Aphasia is not a disease, but a symptom of damage to the parts of the brain that control language. This damage can happen suddenly—like after a stroke or head injury—or slowly over time, as with some neurological conditions.

Some of the most common causes of aphasia include: 

Stroke/Brain Injury:

  • Stroke: The most common cause of aphasia, a stroke occurs when blood flow to the brain is blocked or reduced, depriving brain cells of oxygen. If the language areas of the brain are affected, aphasia can result.
  • Traumatic Brain Injury (TBI): A severe head injury—such as from a car accident, fall, or sports injury—can damage the brain’s language centers and lead to aphasia.
  • Brain Tumors: A tumor (whether cancerous or benign) can press on or grow into brain areas responsible for language, disrupting normal function and communication abilities.
  • Brain Infections: Conditions like encephalitis or meningitis can cause inflammation or damage to brain tissue, sometimes affecting the areas that control speaking, understanding, reading, or writing.

Progressive Neurological Diseases and Primary Progressive Aphasia (PPA):

  • PPA is a type of frontotemporal dementia that starts with language difficulties. Unlike stroke-related aphasia, this etiology will gradually impact other areas of the brain, such as motor abilities and cognitive functioning. 

Aphasia Resources

Join an event!

The National Aphasia Association offers a variety of programs designed to connect, educate, and empower individuals with aphasia and those who support them. From ongoing virtual support groups to aphasia education and training opportunities, our programs are created with accessibility and inclusion at their core. We also host special events throughout the year that celebrate community, raise awareness, and promote learning.