What is aphasia?

Aphasia is a language disorder caused by damage to the parts of the brain that handle language, most often on the left side. The National Institute on Deafness and Other Communication Disorders says it affects speaking and understanding speech, as well as reading and writing. Most people with aphasia are middle-aged or older, but anyone can develop it.

Stroke is the leading cause of aphasia. The National Institute on Deafness and Other Communication Disorders says about one third of stroke survivors have it. Aphasia can also follow a head injury or brain surgery, develop gradually from a brain tumor, or result from brain infections. In people with Alzheimer's or another dementia, it can appear slowly as the disease reaches the brain's language areas.

It can be. The National Institute on Deafness and Other Communication Disorders says people with Alzheimer's, frontotemporal dementia or other dementias may develop aphasia as the disease reaches the language areas of the brain. In some people, aphasia is the first and most noticeable symptom, which is called primary progressive aphasia. Aphasia after a stroke is different, because it is not progressive.

Aphasia is usually divided into fluent and nonfluent types. The National Institute on Deafness and Other Communication Disorders says people with Wernicke's aphasia, a fluent type, may speak in long sentences with little meaning and struggle to understand language. People with Broca's aphasia, a nonfluent type, speak in short, effortful phrases. Global aphasia, from wider damage, causes severe difficulty speaking and understanding.

Aphasia is treated mainly with speech-language therapy. The National Institute on Deafness and Other Communication Disorders says therapy helps people use the language they still have, restore what they can, and communicate in other ways, such as gestures, pictures or electronic devices. Families help by using short sentences, cutting background noise, allowing plenty of time, and not correcting the person's speech.