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 get frustrated when others don't understand.

How is aphasia treated? 

A speech and language therapist (SLT) usually diagnoses the condition by testing your language capabilities. They can also help arrange treatment.

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 and also 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. However, 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, but most people with aphasia make some degree of recovery, and some recover fully. Even if aphasia persists, it does not mean a person is unable to live an independent and meaningful life.

However, the chances of recovery for people with aphasia related to progressive neurological conditions is poor. This is because there is no way of repairing or preventing 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 on developing other ways of communicating, to prepare for a time when speaking will be more difficult.


The challenges of living with aphasia can impact on how a person feels and interacts with others. In some cases it can led to:




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.

Who is affected?

Aphasia is one of the most common communication disorders to affect the brain. Although there are no official figures, the Stroke Association estimates more than 376,000 stroke survivors in the UK are living with aphasia.

Aphasia can affect people of all ages, including children. It's most common in people over 65 years old as stroke and common progressive neurological conditions tend to affect older adults.

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 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 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

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 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. 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.

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, and 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.

Causes of aphasia 

Aphasia is the result of damage to the parts of the brain involved in speaking, reading, writing and understanding others.

Any damage to the language areas of the brain can result in loss of function, leading to aphasia. The severity of a person's aphasia depends on the location and type of injury sustained by the brain.

Aphasia can occur by itself, or alongside other disorders such as visual difficulties, mobility problems, limb weakness and cognitive changes.

Aphasia affects a person’s language but it doesn't affect a person’s intelligence.

Brain damage

Ways the brain can become damaged include:

stroke – during a stroke the brain is deprived of blood and oxygen, which leads to the death of brain tissue

severe head injury – for example, an injury as a result of a road traffic accident or following a serious fall from height

brain tumour – where an abnormal growth of cells develops inside the brain

health conditions that cause progressive loss of cells from the brain, such as dementia. Parkinson's disease does not cause aphasia, but some very similar conditions may do so, such asprogressive supranuclear palsy (PSP) or corticobasal degeneration (CBD)

infections that affect the brain, such as meningitis (an infection of the outer layer of the brain) and encephalitis (an infection of the brain itself), although this is a much rarer cause of aphasia


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 at specialist centres.

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). If you were admitted to hospital, there should be a speech and language therapy team there. 

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.

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. For many people, the most obvious recovery happens in the first six months. 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 your 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 individual sessions, groups, or using technology such as computer programmes or apps.


The treatment you receive will depend on your general health and the difficulties you have with your 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 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 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 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 are 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. 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 for you to communicate. Your therapist will help you develop alternatives to talking, such as using gesture, 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 you 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 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 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 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 you 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

Research is currently being carried out 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. You can search the database of clinical trials for aphasia to find trials that are studying these treatments.

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 after the onset of symptoms. People with aphasia often have complex needs and their condition can make them prone to mood swings and challenging behaviour.

If you are caring for someone with aphasia, you may find the Care and support section of this website useful, particularly the sections aboutcommunication problems and for those who are new to caring.

Speakability, Connect and The Stroke Association are the main UK charities that provide help and support for people affected by aphasia.