Aphasia is when a person has difficulty with their language or speech.  It's usually caused by damage to the left side of the brain (for example, after a stroke).

Symptoms of aphasia

People with aphasis often have trouble with the 4 main ways people understand and use lanaguge.

These are:

  • reading
  • listening
  • speaking
  • typing or writing

Speaking problems are perhaps the most obvious, and people with aphasia may make mistakes with the words they use.

This could be sometimes using the wrong sounds in a  word, choosing the wrong word, or putting words together incorrectly.

Although aphasia affects a person's ability to communicate, it doesn't affect their intelligence.

Aphasia can occur by itself or alongside other disorders, such as visual difficulties, mobility problems, limb weakness, and problems with memory or thinking skills.

Types of aphasia

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

But most people with aphasia have some trouble with their speaking, and will have a mixture of problems with writing, reading and perhaps listening.

Symptoms can range widely from getting a few words mixed up to having difficulty with all forms of communication.

Some people are unaware that their speech makes no sense and get frustrated when others don't understand them.

Causes of aphasia

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

Common causes include:

  • stroke - the most common cause of aphasia
  • severe head injury
  • a brain tumour
  • progressive neurological conditions - conditions that cause the brain and nervous sysytem to become damaged over time, such as dementia.

Aphasia can affect people of all ages, but it's most common in people over the age of 65. This is because strokes and progressive neurological conditions tend to affect older adults.

Diagnosing aphasia

Aphasia is usually diagnosed after tests carried out by a clinician – either a speech and language therapist or a doctor. They can also help arrange treatment if necessary.

These tests often involve simple exercises, such as asking a person to name objects in the room, repeat words and sentences, and read and write.

The aim of these tests is to understand a person's ability to:

  • understand basic speech and grammar
  • express words, phrases and sentences
  • socially communicate – for example, hold a conversation or understand a joke
  • read and write letters, words and sentences

Imaging techniques such as a CT scan or MRI scan can be used to assess brain damage.

Treating aphasia

Speech and language therapy is the main type of treatment for people with aphasia.

This aims to help restore some of your ability to communicate, as well as help you develop alternative ways of communicating, if necessary.

You may receive speech and language therapy on an individual basis or in a group, depending on your needs and the service provided.

An increasing number of computer-based applications are available to support people with aphasia.

But it's important to start using these with the assistance of a speech and language therapist.

How successful treatment is differs from person to person. Most people with aphasia make some degree of recovery, and some recover fully.

If the aphasia is caused by a one-off event, like a stroke, most patients recover to some degree with therapy. There's no evidence to suggest that recovery stops at a specific time after stroke.

But the chances of recovery is poorer for people with aphasia resulting from a progressive neurological condition.

Some people can still respond to therapy, but there are currently no good ways of reversing the ongoing injury to the brain.

When aphasia is caused by a progressive condition, treatment focuses on making the most of what people can still do and developing other ways of communicating to prepare for a time when speaking will be more difficult.

Complcations of aphasia

The challenges of living with aphasia can impact how a person feels and interacts with others.

In some cases, it can lead to:

  • isolation
  • anxiety
  • depression

If you're concerned about someone with aphasia, encourage them to discuss any problems with their GP or a member of their care team to access the relevant support.

If the person is unable to do this themselves, they may require someone to communicate on their behalf.


Aphasia affects everyone differently, but most people will have difficulty expressing themselves or understanding things they hear or read.

If aphasia has been caused by a sudden brain injury, such as a a stroke or a severe head injury, symptoms will usually develop straight after the injury.

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

Someone with expressive aphasia experiences difficulty communicating their thoughts, ideas and messages to others.

This may affect speech, writing, gestures or drawing, and causes problems with everyday tasks like 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 – with difficulty constructing a sentence
  • struggling to get certain words out – such as the names of objects, places or people
  • only using basic nouns and verbs – for example, "want drink" or "go town today"
  • spelling or grammatical errors
  • using a wrong but related word – such as saying "chair" instead of "table"
  • including nonsense words or their speech not making sense (speech-sound errors)

Receptive aphasia

A person with receptive aphasia experiences difficulty understanding things they hear or read. They may also have 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 that may not make sense if they've misunderstood questions or comments
  • not being aware of their difficulties with understanding, or their own speech errors

Aphasia symptoms associated with dementia

People with the most common types of dementia, such as Alzheimer's disease and vascular dementia, usually have a mild form of aphasia.

This often involves problems finding words and can affect names, even of people they know well.

It doesn't mean they don't recognise the person or don't know who they are, they just can't access the name or get mixed up.

Primary progressive aphasia

This is a rare type of dementia, where language is heavily affected. As it's a primary progressive condition, the 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.

The problems gradually get worse, and can include:

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

A person with PPA may also experience other symptoms later in their illness, including:


The recommended treatment for aphasia is usually speech and language therapy. Sometimes aphasia improves on its own without treatment.

This treatment is carried out by a speech and language therapist (SLT). If you were admitted to hospital, there should be a speech and language therapy team there.

When you leave hospital, an SLT should be available through a community rehabilitation team or, after a stroke, an early supported discharge team.

If you weren't admitted to hospital or didn't see an SLT while you were there, you can ask your GP to refer you.

In some areas, you can contact your local speech and language therapy department directly.

Most people with aphasia need many hours of speech and language therapy to recover to their full potential.

How speech and language therapy can help

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

  • help restore as much of your speech and language as possible (reduce impairment)
  • help you communicate to the best of your ability (increase activity and participation)
  • find alternative ways of communicating (use compensatory strategies or aids)
  • provide information to patients and their relatives about aphasia

How the therapy is carried out will depend on your circumstances.

An intensive course of speech and language therapy may be recommended for some people. This involves a number of sessions given in a shorter period of time.

But speech and language therapy can be exhausting, and an intensive course of treatment won't be suitable for everyone.

For some people, shorter and less intensive sessions may be recommended.

Therapy may be individual sessions, in groups, or using technology such as computer programmes or apps.

For many people with aphasia caused by stroke, the most rapid changes are early on in the weeks and months after their stroke.

But improvements can continue to be seen many years, and even decades, later.

Assessment before therapy

The treatment you receive will depend on your general health and the difficulties you have with your speech, language or social skills.

An assessment will be carried out before therapy begins so the therapist can identify which aspects of language you have the most difficulty with.

A therapist will talk to you and your family to try to determine whether your problems are related to understanding language or if you have problems expressing yourself.

The assessment will then focus on the areas that need to be targeted in therapy.

Other health problems that may impact 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.

If you have difficulty understanding words, your SLT may ask you to carry out tasks such as matching words to pictures or sorting words by their meaning.

The aim of these tasks is to improve your ability to remember meanings and link them with other words.

If you have difficulty expressing yourself, your SLT may ask you to practise naming pictures or judge whether certain words rhyme.

They may also ask you to repeat words that they say, with prompting if necessary.

If you're able to complete tasks with single words, your therapist will work on your ability to construct sentences.

Some techniques may involve working with a computer. Other methods may include group therapy with other people with aphasia, or working with family members.

This will allow you to practise 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. But it's important to start using these with the supervision of an SLT.

Alternative methods of communication

An important part of speech therapy is finding different ways for you to communicate.

Your therapist will help you develop alternatives to talking, such as using gestures, writing, drawing or communication charts.

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.

For some people, specially designed electronic 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 you have difficulty speaking but are able to write or type.

There are also apps available on smartphones and computer tablets that can do this.

If a communication device is thought to be beneficial, funding for the purchase of an individual device can be discussed with an SLT.

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 the person plenty of time to respond. If a person with aphasia feels rushed or pressured to speak, they may become anxious, which can affect their ability to communicate.
  • Use short, uncomplicated sentences, and don't 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 don't understand something a person with aphasia is trying to communicate, don't pretend you understand. The person may find this patronising and upsetting.
  • Use visual references, such as pointing, gesturing and objects, to support their understanding.
  • If they're 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.

Ongoing research

Research is currently being carried out to study whether other treatments can benefit people with aphasia.

These include:

  • behavioural therapies or practise – for example, apps to help people gain large amounts of repetitive practise on certain language tasks
  • electrical brain stimulation techniques – for example, transcranial direct current stimulation (tDCS), where a small electrical current is passed through the scalp into the brain to help boost performance on language tasks
  • medicines – for example, to help the brain recover or replace damaged neurotransmitters (chemicals in the brain that allow the nervous system to communicate with the rest of the body)

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

Advice for carers

Helping to care for a loved one, relative or friend with aphasia can be a daunting and challenging prospect, particularly during the first few months of symptoms starting.

People with aphasia often have complex needs, and their condition can make them prone to mood swings and challenging behaviour.

If you're caring for someone with aphasia, you may find the Carers section of this website useful, particularly the section on communicating with someone with dementia.

The Stroke Association provides help and support for people affected by aphasia.

The Aphasia Alliance is a group of organisations that support people with aphasia and their families.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website nhs.uk
Last Updated: 29/11/2021 13:56:46