Autistic spectrum disorder (ASD) is a condition that affects how the brain functions. It affects how a person communicates with, and relates to, other people.

It also affects how they make sense of the world around them.
A person who has autism is said to have ASD.

This is because the symptoms of autism can vary from person to person, and can range from mild to very severe. Aspergers syndrome is an ASD, on the mild end of the spectrum.

The first symptoms of ASD usually appear when the person is under two years old, and last throughout life. Some people who have autism also have a learning difficulty.

This is when they find it harder than most people to learn new skills.

The cause of ASD is unknown, although some research has shown that a gene may be involved and a tendency to ASD may be inherited from your parents. You have a higher chance of having it if a brother or sister has the condition.

There is also some evidence that ASD may be caused by factors in the environment.

Research suggests that 2-3 people in every 1,000 have ASD in the UK. It affects three times as many males than females, although the reason for this is unknown.

There is no cure for ASD and it continues throughout life. However, there are many treatments and types of support available that can help to control the symptoms.


The symptoms of autistic spectrum disorder (ASD) can vary in severity from person to person. Thats why autism is usually referred to as a spectrum disorder because a person who has autism can have a range of symptoms.

Symptoms of ASD can be divided into three main groups. They are:

  • social interaction,
  • communication, and
  • routine and repetitive behaviour.

The symptoms are often noticed within the first three years of a childs life. The child will usually show signs of normal development before symptoms begin. Some children with severe ASD may never learn skills such as speaking.

Some people with ASD will have a learning disability. This is when they find it harder than most people to learn new skills. However, many people will have average or above-average intelligence.

Social Interaction

A child who has ASD may find it hard to get on with other people.

They may:

  • seem distant or detached,
  • have little or no interest in other people, and find it difficult make friends,
  • not seek affection in the usual way, or resist physical contact such as kissing and cuddling,
  • find it difficult to make eye contact with other people,
  • not understand other peoples emotions, and
  • prefer to spend time alone.


A child who has ASD may develop speech later than other children, or never learn to speak. When their speech does develop, the language and choice of words they use may be wrong.
A child with ASD may also:

  • not be able to express themselves well,
  • not be able to understand gestures, facial expressions, or tones of voice,
  • use odd phrases and use odd choices of words,
  • use more words than is necessary to explain simple things,
  • make up their own words or phrases,
  • not use their hands to make gestures when they speak, and
  • find it difficult to understand difficult commands.

Routine & Repetitive Behaviour

Children with ASD may:

  • play the same games over and over, or play with games designed for children younger than themselves,
  • get upset if their daily routines are interrupted in any way, and
  • repeat actions, such as rocking back and forth or head banging.

These symptoms may lead to hyperactivity in younger children.
Older children and adults may develop obsessions. For example, with specific objects, lists, timetables or routines.

Sensory Difficulties

Some children with ASD also have sensory difficulties. This means that they may get upset if they are over or under stimulated. For example, they may prefer being indoors if they are over sensitive to light, or they may bump into people if they are under sensitive to touch.
Sensory difficulties can also lead to problems with movement. A person with ASD may appear clumsy or have an unusual way of walking.

Aspergers Syndrome

Aspergers syndrome is milder form of ASD. People with Aspergers syndrome will not have a learning disability and are often of average or above average intelligence. Many people with Aspergers syndrome are very good at learning facts and figures.

People with Aspergers are likely to like keeping to routines. Although they usually have fewer problems with language than people with more severe ASD, they may also find it hard to understand gestures and facial expressions so they find social interaction difficult.
Because Aspergers syndrome is a mild form of ASD, symptoms are harder to spot, and this can cause a delay in getting the correct diagnosis.


Symptoms of ASD are caused by an abnormality in the development of the brain that occurs before, or soon after birth. It is not known exactly what causes this abnormality.

Some evidence shows that having a defective gene may be a risk factor in developing ASD. These genes may be inherited, and the chance of you having ASD if your brother or sister has it, is slightly higher than in the rest of the general population.

Some research suggests that environmental factors such as pollution or viruses such as rubella (German measles) may trigger ASD. However, ASD is not a result of anything that a parent has done either during pregnancy or after the child is born.

Research shows that there is no link between the MMR vaccine and ASD. Research shows that more children are diagnosed with ASD now than 10 years ago and the number of children receiving the MMR vaccine has stayed the same.


Getting a diagnosis for autistic spectrum disorder (ASD) is important, to enable access to the right services and treatments to support individual needs.

ASD may be difficult to diagnose as symptoms can vary considerably from person to person, and mild symptoms can be hard to spot.

The most common age for diagnosis is between three and four years old. However, some people may not be diagnosed until they are older, especially if they have mild symptoms. ASD isnt usually diagnosed before a child is two years old.

Diagnosis in Children

If you think your child has symptoms of ASD you should speak with your GP. If they are already in school, you may also want to speak to their teacher or school nurse. If your GP thinks that your child has ASD, they may also refer them to another health professional such as a:

  • child psychiatrist (a doctor who specialises in mental health),
  • paediatrician (a doctor who specialises in childrens health), or
  • psychologist (a person who studies behaviour).

Your GP or health professional will make a diagnosis based on you childs symptoms, as well as observation of their communication skills, development and the way that they behave. They may observe them in a situation that your child is familiar with, such as at school or when they are playing with their toys. They may see how your child deals with new places or meeting new people.


There are no specific tests for ASD, although other tests such as hearing tests and blood tests may be done to rule out other health conditions.


There is no treatment that can cure autistic spectrum disorder (ASD). However, there are many ways in which a person with ASD can get support to manage their condition. These methods of management and support are often called interventions. Many people with ASD will require specialist care and support throughout their lives. A lot of different health professionals will work as a team to care for them.

The aim of interventions is to help a person with ASD to speak and communicate better, and to get along better in education and at work. Health professionals think that interventions work better when a child with ASD starts them from a young age.

Because ASD differs from person to person, the type of support a person needs will depend on their own individual circumstances. It will also depend on what services and treatments are available in the area that you live. Not all services are available on the NHS in all areas.

Although not a treatment in itself, a psychologist may set tests to help decide the best treatment options.


When a child is diagnosed with ASD, they will have an assessment of their educational needs. Some children may need to attend a specialist school for children with ASD. Other children with less severe symptoms may be able to attend a mainstream school, but may need extra support away from lesson time. In general, children with ASD do better in school when lessons are well structured.

There is also evidence to suggest that teaching your child at home when they are very young can help them when they start school. However, to do this successfully you need put a lot of time in with your child. There are specialist training courses to learn the skills required, and to understand more about how ASD affects your childs learning. This method is sometimes called applied behavioural analysis.

Communication with Children

Many children with ASD benefit from training on how to communicate in social situations. This can come in the form of a training group, or through behavioural therapies such as counselling and speech therapy. You can communicate more effectively with a person who has ASD by:

  • keeping to predictable routines,
  • avoiding using metaphors and sarcasm,·
  • saying exactly what you mean, and
  • using visual aids where necessary (for example, a fork for mealtimes or towel for bath time).


Medicines can't be used to treat the cause of ASD. However, medicines can be used to control some symptoms such as hyperactivity or obsessional behaviour. For example, a medicine called methylphenidate can make your child less irritable and hyperactive.

However, some medicines used to treat the symptoms of ASD can cause side effects, so your doctor will only use them if the benefits outweigh the risks of taking them.

Other Treatments

  • Auditory integration training (AIT) this is when your child listens to special music so their hearing changes and they arent as bothered by certain sounds. AIT isnt widely available on the NHS in England.
  • The picture exchange communication system (PECS) this is when your child is trained to communicate using pictures that are familiar to them. This type of treatment is especially helpful if they find it hard to communicate through speaking.
  • Sensory integration therapy this is when your child is gently exposed to various stimulants such as noise or touch to improve the way in which they use their senses.

The information shown here is Crown copyright and has been reproduced with the permission of NHS Direct. Last updated June 2007.