Aphasia is a condition that affects the brain and leads to problems using language correctly.

People with aphasia make mistakes in the words they use, sometimes using the wrong sounds in a word, choosing the wrong word, or putting words together incorrectly.

Aphasia also affects speaking and writing in the same way. Many people with the condition find it difficult to understand words and sentences they hear or read.

Why does aphasia happen?

Aphasia is caused by damage to parts of the brain responsible for understanding and using language.

Common causes include:

  • stroke, thought to be the most common cause, around one in three people experience some degree of aphasia after having a stroke
  • severe head injury
  • brain tumour
  • progressive neurological conditions (conditions that over time cause progressive brain and nervous system damage)

Types of aphasia

Aphasia is often classified as ‘expressive’ or ‘receptive’ aphasia, depending on whether there are difficulties with understanding or expressing language, or both.

Symptoms can range from getting a few words mixed up to having difficulty with all forms of communication, such as reading, writing, naming objects and understanding speech.

Some people are unaware their speech makes no sense and this can be very frustrating.


Symptoms of aphasia 

The main sign of aphasia is difficulty with communication, although the condition affects everyone differently.

In cases where aphasia has been caused by a sudden brain injury, such as a stroke or a severe head injury, symptoms occur suddenly.

In cases where there is gradual damage to the brain as a result of a condition that gets worse over time, such as dementia or a brain tumour, the symptoms may develop gradually.

Expressive aphasia

People with expressive aphasia experience difficulty communicating their thoughts, ideas and messages to others. This may affect speech, writing, gestures, or drawing, and causes problems with everyday tasks such as using the telephone, writing an email or speaking to family and friends.

People with expressive aphasia may have some of the following signs and symptoms:

  • slow and halting speech
  • they may struggle to get certain words out, such as the names of objects, places or people
  • the content of their speech is stripped down to simple elements and only contains basic nouns and verbs, for example, “want drink” or “go town today”
  • spelling or grammatical errors
  • using the wrong word, such as saying ‘chair’ instead of ‘table’
  • difficulty contstructing a sentence
  • being able to write or speak fluently, using long sentences, but often including nonsense words or their speech lacks meaning

Receptive aphasia

Difficulty in understanding things is called receptive aphasia. People affected by this condition will also have a difficulty interpreting gestures, drawings, numbers and pictures.

This can affect everyday activities such as reading an email, managing finances, having conversations, listening to the radio or following TV programmes.

People with receptive aphasia may have some of the following signs and symptoms:

  • difficulty understanding what people say
  • difficulty understanding written words
  • misinterpreting the meaning of words, gestures, pictures or drawings
  • giving responses which may not make sense if they’ve misunderstood questions or comments
  • not being aware of their difficulties with understanding

Primary progressive aphasia

This type of aphasia occurs in people with a specific type of dementia. Symptoms get worse over time. Usually, the first problem people with primary progressive aphasia (PPA) notice is difficulty finding the right word or remembering somebody’s name.

Gradually the problems get worse and can include:

  • speech becoming hesitant and difficult and making mistakes with the sounds of words or grammar
  • speech becomes slow with short, simple sentences
  • forgetting the meaning of complicated words, then later also simple ones, making it more difficult for them to understand other people
  • speech becomes more vague and the person has difficulty being specific or clarifying what they’re saying
  • becoming less and less likely to join or start conversations

A person with PPA may also experience other symptoms later in their illness, including changes in their personality and behaviour, difficulties with memory and thinking similar to Alzheimer’s disease, or difficulties with movement similar to Parkinson’s disease.

Diagnosing aphasia 

Aphasia is usually diagnosed after tests carried out by a specialist called a speech and language therapist (SLT).

Communication assessment

There are several tests used to assess communication skills.

These tests often involve simple exercises, such as asking a person to name as many words as they can think of beginning with the letter F, or asking them to name objects in the room. The results can then be used to build up a detailed picture of a person’s capabilities in areas such as:

  • understanding basic speech and grammar
  • expressing words, phrases and sentences
  • social communication – for example, holding a conversation or understanding a joke
  • reading and writing of letters, words and sentences

Imaging scans

Imaging techniques can be used to assess the extent of any brain damage. The two most widely used types for aphasia are:

  • a computerised tomography (CT) scan
  • magnetic resonance imaging (MRI) scan

Less commonly, a positron emission tomography (PET) scan may be used to assess the state and functionality of the brain. PET scans are usually only used to carry out clinical research.


Treating aphasia 

Sometimes aphasia will improve on its own without treatment, but a type of treatment called speech and language therapy is usually recommended.

This treatment is carried out by a speech and language therapist (SLT).

For people with aphasia, speech and language therapy aims to:

  • help you communicate to the best of your ability
  • help restore as much of your speech and language as possible
  • find alternative ways of communicating

Evidence suggests speech and language therapy is more effective if it’s started as soon as possible. Most obvious recovery occurs within the first 6 months of treatment. However, improvements can continue to be seen for much longer after this, even many years later.

How the therapy is carried out will depend on circumstances. An intensive course of speech and language therapy may be recommended for some people. This involves a number of sessions spread out over a shorter period of time.

However, speech and language therapy can be exhausting and an intensive course of treatment will not be suitable for everyone. For some people, shorter and less intensive sessions may be recommended.

Therapy may be done though individual sessions, group sessions, or using technology such as computer programmes or apps.


Treatment will depend on the general health and the difficulties with speech, language or social skills, as there is no universally accepted treatment for aphasia.

An assessment will be carried out before therapy begins so the therapist can identify which aspects of language is affected.

The assessment will then focus on the areas that need to be targeted in therapy. Other health problems that may impact on your ability to communicate, such as hearing or sight problems, will also be taken into account.

Speech and language therapy techniques

The specific techniques used and the aims of the treatment will depend on each person’s circumstances. Some examples are described below.

If the difficulty involves understanding words, the SLT may instruct to carry out tasks such as matching words to pictures or sorting words by their meaning. The aim of these tasks is to improve the ability to remember meanings and link them with other words.

If expressive aphasia is the concern, the SLT guide you in naming pictures or judge whether certain words rhyme. Repetition of words may also be done with prompting if necessary. If you are able to complete tasks with single words, your therapist will work on your ability to construct sentences.

Some techniques may make use of the computer. Other methods may include group therapy with other people with aphasia, or working with family members. This will allow you to practice conversational skills, or rehearse common situations, such as making a telephone call.

An increasing number of computer based programmes and apps are available to help people with aphasia improve their language abilities. However it’s important to start using these alongside a speech and language therapist.

Alternative methods of communication

An important part of speech therapy is finding different ways to communicate. Alternatives to talking, such as using gesture, writing, drawing or communication charts may be taught by the SLT.

Communication charts are large grids containing letters, words or pictures. They allow someone with aphasia to communicate by pointing at the word or letter to indicate what they want to say.

Specially designed devices, such as voice output communication aids (VOCAs), may be useful. VOCAs use a computer-generated voice to play messages aloud. This can help if there is a difficulty in speaking but able to write or type. There are also apps available on smartphones and computer tablets that can do this.

If a communication device is felt to be beneficial, funding for purchase of an individual device can be discussed with a speech and language therapist.

Communicating with a person with aphasia

If you live with or care for a person with aphasia, you may be unsure about the best way to communicate with them. You may find the following advice helpful:

  • After speaking, allow time to respons. If a person with aphasia feels rushed or pressured, they may become anxious, which can affect their ability to communicate.
  • Use short, uncomplicated sentences and do not change the topic of conversation too quickly.
  • Avoid asking open-ended questions. Closed questions that have a yes or no answer can be better.
  • Avoid finishing a person’s sentences or correcting any errors in their language. This may cause resentment and frustration for the person with aphasia.
  • Keep distractions to a minimum, such as background radio or TV noise.
  • Use paper and a pen to write down key words or draw diagrams or pictures to help reinforce your message and support their understanding.
  • If you do not understand something a person with aphasia is trying to communicate, do not pretend to understand. The person may find this patronising and upsetting.
  • Use visual references, such as pointing, gesturing and using objects, to support their understanding.
  • If they are having difficulty finding the right word, prompt them – ask them to describe the word, think of a similar word, try to visualise it, think of the sound the word starts with, try to write the word, use gestures or point to an object.

Other treatments

On going research is done to study whether other treatments can benefit people with aphasia. These include:

  • medication – such as piracetam, bifemelane, piribedil, bromocriptine and idebenone
  • transcranial magnetic stimulation – where an electromagnet placed on the scalp is stimulated for a short time using an electric current to stimulate parts of the brain affected by aphasia

Although some studies have suggested these treatments may benefit some people with aphasia, further research is necessary.

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